Remove 15063 specific fix and redundant code

The fix that was introduced for build 17025 is universal, does not add unneeded files, does not need to be explicitly enabled, and works fine for 15063, so there is no need to keep the old fix.

shared/main.php

@@ -16,7 +16,7 @@ limitations under the License.
 */
 
 function uupApiVersion() {
-    return '1.5.0';
+    return '1.5.1';
 }
 
 function uupApiPrintBrand() {