Gulpfile JS Less почему появляются css 2 файла?

var gulp           = require('gulp'),
    smartgrid      = require('smart-grid');
		gutil          = require('gulp-util' ),
		less           = require('gulp-less'),
		gcmq = require('gulp-group-css-media-queries');
		browserSync    = require('browser-sync'),
		concat         = require('gulp-concat'),
		uglify         = require('gulp-uglify'),
		cleanCSS       = require('gulp-clean-css'),
		rename         = require('gulp-rename'),
		del            = require('del'),
		imagemin       = require('gulp-imagemin'),
		cache          = require('gulp-cache'),
		autoprefixer   = require('gulp-autoprefixer'),
		notify         = require("gulp-notify"),
    sourcemaps = require('gulp-sourcemaps');


gulp.task('grid', function() {
    smartgrid('src/less', {
    outputStyle: 'less', /* less || scss || sass || styl */
    columns: 12, /* number of grid columns */
    offset: '30px', /* gutter width px || % */
    mobileFirst: false, /* mobileFirst ? 'min-width' : 'max-width' */
    container: {
        maxWidth: '1200px', /* max-width оn very large screen */
        fields: '30px' /* side fields */
    },
    breakPoints: {
        lg: {
            width: '1200px', /* -> @media (max-width: 1100px) */
        },
        md: {
            width: '992px'
        },
        sm: {
            width: '768px',
            fields: '15px' /* set fields only if you want to change container.fields */
        },
        xs: {
            width: '560px'
        }
        /* 
        We can create any quantity of break points.

        some_name: {
            width: 'Npx',
            fields: 'N(px|%|rem)',
            offset: 'N(px|%|rem)'
        }
        */
    }
  });
});



gulp.task('common-js', function() {
	return gulp.src([
		'src/js/common.js',
		])
	.pipe(concat('common.min.js'))
	.pipe(uglify())
	.pipe(gulp.dest('src/js'));
});

gulp.task('js', ['common-js'], function() {
	return gulp.src([
		//'src/libs/jquery/dist/jquery.min.js',
		'src/js/common.min.js',
		])
	.pipe(concat('scripts.min.js'))
	.pipe(gulp.dest('src/js'))
	.pipe(browserSync.reload({stream: true}));
});

gulp.task('browser-sync', function() {
	browserSync({
		server: {
			baseDir: 'src'
		},
		notify: false,
	});
});

gulp.task('less', function() {
	return gulp.src('src/less/**/*.less')
	.pipe(less({outputStyle: 'expand'}).on("error", notify.onError()))
	.pipe(rename({suffix: '.min', prefix : ''}))
	.pipe(autoprefixer(['last 15 versions']))
	.pipe(gcmq())
	.pipe(sourcemaps.init())
	.pipe(cleanCSS()) 
	.pipe(sourcemaps.write())
	.pipe(gulp.dest('src/css'))
	.pipe(browserSync.reload({stream: true}));
});

gulp.task('watch', ['less', 'js', 'browser-sync'], function() {
	gulp.watch('src/less/**/*.less', ['less']);
	gulp.watch(['libs/**/*.js', 'src/js/common.js'], ['js']);
	gulp.watch('src/*.html', browserSync.reload);
});

gulp.task('imagemin', function() {
	return gulp.src('src/img/**/*')
	.pipe(cache(imagemin())) // Cache Images
	.pipe(gulp.dest('dist/img')); 
});

gulp.task('build', ['removedist', 'imagemin', 'less', 'js'], function() {

	var buildFiles = gulp.src([
		'src/*.html',
		'src/.htaccess',
		]).pipe(gulp.dest('dist'));

	var buildCss = gulp.src([
		'src/css/main.min.css',
		]).pipe(gulp.dest('dist/css'));

	var buildJs = gulp.src([
		'src/js/scripts.min.js',
		]).pipe(gulp.dest('dist/js'));

	var buildFonts = gulp.src([
		'src/fonts/**/*',
		]).pipe(gulp.dest('dist/fonts'));

});

gulp.task('removedist', function() { return del.sync('dist'); });
gulp.task('clearcache', function () { return cache.clearAll(); });

gulp.task('default', ['watch']);