Slight fix for gclient readability

gclient.py

Index: gclient.py
diff --git a/gclient.py b/gclient.py
index 9bc21e5a5535afd2a6a322c628d07157dc7b9f72..a1d6f2e0015ecc82b0b2e38dfaa29d56a6ec57f6 100755
--- a/gclient.py
+++ b/gclient.py
@@ -1481,11 +1481,11 @@ been automagically updated.  The previous version is available at %s.old.
       return revision_overrides
     solutions_names = [s.name for s in self.dependencies]
     for i, revision in enumerate(self._options.revisions):
-      if not '@' in revision:
+      if '@' in revision:
+        name, rev = revision.split('@', 1)
+      else:
         # Support for --revision 123
         name, rev = solutions_names[i], revision
-      else:
-        name, rev = revision.split('@', 1)
       revision_overrides[name] = rev
     return revision_overrides