Bump gulp-terser from 1.2.0 to 1.2.1

Bumps [gulp-terser](https://github.com/duan602728596/gulp-terser) from 1.2.0 to 1.2.1.
- [Release notes](https://github.com/duan602728596/gulp-terser/releases)
- [Commits](https://github.com/duan602728596/gulp-terser/compare/v1.2.0...v1.2.1)

Signed-off-by: dependabot[bot] <support@github.com>

package.json

@@ -31,7 +31,7 @@
     "gulp-run": "^1.7.1",
     "gulp-sass": "^4.0.2",
     "gulp-sourcemaps": "^2.6.5",
-    "gulp-terser": "^1.2.0",
+    "gulp-terser": "^1.2.1",
     "localtunnel": "^2.0.0",
     "lodash": "^4.17.13",
     "lodash.template": "^4.5.0",