Use the new incremental import style by default

Signed-off-by: Simon Hausmann <shausman@trolltech.com>

contrib/fast-import/git-p4

@@ -751,6 +751,7 @@ class GitSync(Command):
 
         if len(self.branch) == 0:
             self.branch = "p4"
+
         if len(args) == 0:
             if not gitBranchExists(self.branch) and gitBranchExists("origin"):
                 if not self.silent: