GP-4937: Fixing zipExtension dependencies

gradle/support/extensionCommon.gradle

@@ -4,9 +4,9 @@
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
- * 
+ *
  *      http://www.apache.org/licenses/LICENSE-2.0
- * 
+ *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
@@ -16,6 +16,8 @@
 import org.apache.tools.ant.filters.*
 
 task zipExtensions (type: Zip) {
+	dependsOn ':assembleSource'
+
 	def p = this.project
 	
 	it.group 'private'