Change method of fetching updates to more foolproof

Fixes fetching of Release Preview for Fall Creators Update

shared/main.php

@@ -16,7 +16,7 @@ limitations under the License.
 */
 
 function uupApiVersion() {
-    return '1.1.2';
+    return '1.2.0';
 }
 
 function uupApiPrintBrand() {