convert: raise Abort instead of NoRepo when CVS pserver auth fails.

At this point we know the source is CVS, so we should not go through
the rest of the converters.

hgext/convert/cvs.py

@@ -153,7 +153,7 b' class convert_cvs(converter_source):'
                 sck.send("\n".join(["BEGIN AUTH REQUEST", root, user, passw,
                                     "END AUTH REQUEST", ""]))
                 if sck.recv(128) != "I LOVE YOU\n":
-                    raise NoRepo("CVS pserver authentication failed")
+                    raise util.Abort("CVS pserver authentication failed")
 
                 self.writep = self.readp = sck.makefile('r+')