Fixed NPE with getUploadParamsForTemplate API call

if isdynamicallyscalable optional parameter is not specified, its trying
to cast null to Boolean and throws NPE

api/src/org/apache/cloudstack/api/command/user/template/GetUploadParamsForTemplateCmd.java

@@ -109,6 +109,9 @@ public class GetUploadParamsForTemplateCmd extends AbstractGetUploadParamsCmd {
     }
 
     public Boolean isDynamicallyScalable() {
+        if (isDynamicallyScalable == null) {
+            return Boolean.FALSE;
+        }
         return isDynamicallyScalable;
     }