Bump vue-template-compiler

Bumps [vue-template-compiler](https://github.com/vuejs/vue) from 2.5.20 to 2.5.21.
- [Release notes](https://github.com/vuejs/vue/releases)
- [Commits](https://github.com/vuejs/vue/compare/v2.5.20...v2.5.21)

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

apps/updatenotification/package-lock.json

@@ -1577,7 +1577,8 @@
         "ansi-regex": {
           "version": "2.1.1",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "aproba": {
           "version": "1.2.0",
@@ -1992,7 +1993,8 @@
         "safe-buffer": {
           "version": "5.1.1",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "safer-buffer": {
           "version": "2.1.2",
@@ -2048,6 +2050,7 @@
           "version": "3.0.1",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "ansi-regex": "^2.0.0"
           }
@@ -2091,12 +2094,14 @@
         "wrappy": {
           "version": "1.0.2",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "yallist": {
           "version": "3.0.2",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         }
       }
     },
@@ -4416,9 +4421,9 @@
       }
     },
     "vue-template-compiler": {
-      "version": "2.5.20",
-      "resolved": "https://registry.npmjs.org/vue-template-compiler/-/vue-template-compiler-2.5.20.tgz",
-      "integrity": "sha512-aGJRLd1bJZi6oerGwCQVaDqvQ1T3dhCbNg9C2gNwzoKnyA3BmYfAWy8OQ3OhOebTri8o4YcLeXfwOOxtOKFfmA==",
+      "version": "2.5.21",
+      "resolved": "https://registry.npmjs.org/vue-template-compiler/-/vue-template-compiler-2.5.21.tgz",
+      "integrity": "sha512-Vmk5Cv7UcmI99B9nXJEkaK262IQNnHp5rJYo+EwYpe2epTAXqcVyExhV6pk8jTkxQK2vRc8v8KmZBAwdmUZvvw==",
       "dev": true,
       "requires": {
         "de-indent": "^1.0.2",

apps/updatenotification/package.json

@@ -32,7 +32,7 @@
     "css-loader": "^2.0.0",
     "file-loader": "^1.1.11",
     "vue-loader": "^15.4.2",
-    "vue-template-compiler": "^2.5.20",
+    "vue-template-compiler": "^2.5.21",
     "webpack": "^4.27.1",
     "webpack-cli": "^3.1.2",
     "webpack-merge": "^4.1.5"