fix git pull error

ellipsyswrapper/testsuite.py

@@ -164,7 +164,10 @@ class CaseRunner(object):
                             os.system('git remote set-url origin %s' % url2) 
                         command = 'git pull origin %s' % self.make_test_data_branch
                         print('checking remote branch %s for updates' % self.make_test_data_branch, flush=True)
-                        status = subprocess.check_output(command, shell=True)
+                        try:
+                            status = subprocess.check_output(command, shell=True)
+                        except:
+                            print("no updates")
                         command = 'git push origin %s' % self.make_test_data_branch
                         print('pushing code with ellipsys_ci_bot user', flush=True)
                         status = subprocess.check_output(command, shell=True)