Print stderr output from git command for RemoteFetch

The stderr output generated by git during a RemoteFetch was not being
printed.  This information is useful so print it.

Change-Id: I6e6ce12c4a57e5ca2359f76ce14f2fcbbc37a5ef

project.py

@@ -1877,6 +1877,7 @@ class Project(object):
       gitcmd = GitCommand(self, cmd, bare=True, capture_stderr=True,
                           ssh_proxy=ssh_proxy)
       ret = gitcmd.Wait()
+      print(gitcmd.stderr, file=sys.stderr, end='')
       if ret == 0:
         ok = True
         break
@@ -1886,8 +1887,9 @@ class Project(object):
             "git remote prune" in gitcmd.stderr):
         prunecmd = GitCommand(self, ['remote', 'prune', name], bare=True,
                               capture_stderr=True, ssh_proxy=ssh_proxy)
-        if prunecmd.Wait():
-          print(prunecmd.stderr, file=sys.stderr)
+        ret = prunecmd.Wait()
+        print(prunecmd.stderr, file=sys.stderr, end='')
+        if ret:
           break
         continue
       elif current_branch_only and is_sha1 and ret == 128: