disable link action in courseware, re #35

resources/vue/components/courseware/structural-element/CoursewareStructuralElementDialogAddChooser.vue

@@ -20,7 +20,7 @@
                     @click="selectType('copy')"
                 />
                 <studip-square-button
-                    v-if="inCourseContext && userIsTeacher"
+                    v-if="false"
                     icon="group"
                     :title="$gettext('Aus Arbeitsplatz verknüpfen')"
                     @click="selectType('link')"