add: check does com.apple.Push attribute exist in .pbxproj to avoid not found error.

hooks/iosDisablePush.js

@@ -41,6 +41,7 @@ let disablePushNotificationForXCode = (entitlementsPath, pbxprojPath) => {
         // turn off Push Notification Capability
         let re4rep = new RegExp('isa = PBXProject;(.|[\r\n])*TargetAttributes(.|[\r\n])*SystemCapabilities(.|[\r\n])*com\.apple\.Push = {(.|[\r\n])*enabled = [01]');
         let parts = re4rep.exec(data);
+        if(parts !== null && parts !== undefined && parts.length > 0) {
             result = data.replace(re4rep, parts[0].substr(0, parts[0].length - 1) + '0');
         
             // write result to project.pbxproj
@@ -50,6 +51,7 @@ let disablePushNotificationForXCode = (entitlementsPath, pbxprojPath) => {
                 }
                 console.log(pbxprojPath + " written successfully");
             });
+        }
     });
 }