url-checkers: raise UrlError on acutally failed calls to the path, before we leaked org requests exception out

vcsserver/remote/git_remote.py

@@ -484,9 +484,9 b' class GitRemote(RemoteBase):'
         q = {"service": 'git-upload-pack'}
         qs = f'?{urllib.parse.urlencode(q)}'
         cu = f"{test_uri}{qs}"
-        req = urllib.request.Request(cu, None, {})
 
         try:
+            req = urllib.request.Request(cu, None, {})
             log.debug("Trying to open URL %s", obfuscated_uri)
             resp = o.open(req)
             if resp.code != 200:
@@ -502,7 +502,7 b' class GitRemote(RemoteBase):'
         if b'service=git-upload-pack' in gitdata:
             pass
         elif re.findall(br'[0-9a-fA-F]{40}\s+refs', gitdata):
-            # old style git can return some other format !
+            # old style git can return some other format!
             pass
         else:
             e = None

vcsserver/remote/hg_remote.py

@@ -501,9 +501,9 b' class HgRemote(RemoteBase):'
         q.update({'pairs': "{}-{}".format('0' * 40, '0' * 40)})
         qs = f'?{urllib.parse.urlencode(q)}'
         cu = f"{test_uri}{qs}"
-        req = urllib.request.Request(cu, None, {})
 
         try:
+            req = urllib.request.Request(cu, None, {})
             log.debug("Trying to open URL %s", obfuscated_uri)
             resp = o.open(req)
             if resp.code != 200: