Bump vue-loader from 15.7.2 to 15.8.3

Bumps [vue-loader](https://github.com/vuejs/vue-loader) from 15.7.2 to 15.8.3.
- [Release notes](https://github.com/vuejs/vue-loader/releases)
- [Changelog](https://github.com/vuejs/vue-loader/blob/master/CHANGELOG.md)
- [Commits](vuejs/vue-loader@v15.7.2...v15.8.3)

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

Author: dependabot-preview[bot]

package-lock.json

@@ -32,7 +32,7 @@
     "css-loader": "^3.4.0",
     "node-sass": "^4.13.0",
     "sass-loader": "^7.3.1",
-    "vue-loader": "^15.7.2",
+    "vue-loader": "^15.8.3",
     "vue-template-compiler": "^2.6.11",
     "webpack": "^4.41.2",
     "webpack-cli": "^3.3.10",