ubuntu-build: For some reasons, now you need to be authenticated before trying to use the "PersonTeam" class features.

Do it at the begin instead of replicating the same code inside the tool itself.

This fixes e.g. this failure:

./ubuntu-build --batch --retry morsmall
Traceback (most recent call last):
  File "/tmp/ubuntu-dev-tools/ubuntu-build", line 317, in <module>
    main()
  File "/tmp/ubuntu-dev-tools/ubuntu-build", line 289, in main
    can_retry = args.retry and me.canUploadPackage(
AttributeError: 'NoneType' object has no attribute 'canUploadPackage'

ubuntu-build

@@ -117,6 +117,13 @@ def main():
     # Parse our options.
     args = parser.parse_args()
 
+    try:
+        # Will fail here if we have no credentials, bail out
+        Launchpad.login()
+    except TokenAuthorizationException:
+        sys.exit(1)
+    me = PersonTeam.me
+
     if not args.batch:
         # Check we have the correct number of arguments.
         if len(args.packages) < 3:
@@ -153,13 +160,6 @@ def main():
             Logger.error(error)
             sys.exit(1)
 
-        try:
-            # Will fail here if we have no credentials, bail out
-            Launchpad.login()
-        except TokenAuthorizationException:
-            sys.exit(1)
-
-        # Get the ubuntu archive
         ubuntu_archive = Distribution("ubuntu").getArchive()
         # Get list of published sources for package in question.
         try:
@@ -178,7 +178,6 @@ def main():
         # Operations that are remaining may only be done by Ubuntu developers
         # (retry) or buildd admins (rescore). Check if the proper permissions
         # are in place.
-        me = PersonTeam.me
         if operation == "rescore":
             necessary_privs = me.isLpTeamMember("launchpad-buildd-admins")
         if operation == "retry":
@@ -268,7 +267,6 @@ def main():
     except SeriesNotFoundException as error:
         Logger.error(error)
         sys.exit(1)
-    me = PersonTeam.me
 
     # Check permisions (part 1): Rescoring can only be done by buildd admins
     can_rescore = args.priority and me.isLpTeamMember("launchpad-buildd-admins")