Remove cloning control stub.

Cloning takes place from the project list, we don't really need
to duplicate that functionality here for the time being.

lib/www/client/source/src/views/ProjectSettings.vue

@@ -21,37 +21,6 @@
       </v-row>
     </v-overlay>
 
-    <v-row>
-      <v-col>
-        <v-dialog
-          max-width="600px"
-          :value="dialog"
-          @input="closeDialog"
-        >
-          <template v-slot:activator="{ on, attrs }">
-            <v-btn v-if="writeaccess"
-              small
-              color="teal" dark
-              v-bind="attrs"
-              v-on="on"
-              title="Create a new survey based on this one by changing only a few settings"
-            >Clone survey</v-btn>
-          </template>
-          <v-card>
-            <v-card-title>Create a survey based on this one</v-card-title>
-            <v-card-text>
-              <p>Only a subset of fields will be changed.</p>
-              <v-container>
-                <v-row>
-                  <v-col cols="12">
-                  </v-col>
-                </v-row>
-              </v-container>
-            </v-card-text>
-          </v-card>
-        </v-dialog>
-      </v-col>
-    </v-row>
     <v-row>
       <v-col cols="4">
         <v-toolbar