Fix problem with code signing script (sign.py) not being invoked properly on...

Fix problem with code signing script (sign.py) not being invoked properly on some systems.  Changed "sign.py filename" to "python sign.py filename".  Reviewed with bos and kelly.

indra/newview/viewer_manifest.py

@@ -386,7 +386,10 @@ def package_finish(self):
         # If we're on a build machine, sign the code using our Authenticode certificate. JC
         sign_py = 'C:\\buildscripts\\code-signing\\sign.py'
         if os.path.exists(sign_py):
-            self.run_command(sign_py + ' ' + self.dst_path_of(installer_file))
+            # Appears to require the "python" command to pass a proper argv
+            # to the script, but only on certain systems.  JC
+            self.run_command('python ' + sign_py + ' ' +
+                    self.dst_path_of(installer_file))
         else:
             print "Skipping code signing,", sign_py, "does not exist"
         self.created_path(self.dst_path_of(installer_file))