Update vue monorepo to v2.6.12 (#215)

Update vue monorepo to v2.6.12

Reviewed-on: https://kolaente.dev/vikunja/frontend/pulls/215

package.json

@@ -19,7 +19,7 @@
     "snake-case": "3.0.3",
     "v-tooltip": "2.0.3",
     "verte": "0.0.12",
-    "vue": "2.6.11",
+    "vue": "2.6.12",
     "vue-advanced-cropper": "0.16.10",
     "vue-drag-resize": "1.4.2",
     "vue-easymde": "1.2.2",
@@ -48,7 +48,7 @@
     "vue-multiselect": "2.1.6",
     "vue-notification": "1.3.20",
     "vue-router": "3.4.3",
-    "vue-template-compiler": "2.6.11"
+    "vue-template-compiler": "2.6.12"
   },
   "eslintConfig": {
     "root": true,