Make version same as pypi.

Before running twine upload dist/*, execute python setup.py build_trans -D and python setup.py build_plugins to make translations and plugins included in source distribution, after that, run python setup.py sdist to create the source distribution.

setup.py

@@ -188,7 +188,7 @@ def run(self):
 # Main setup
 setup(
     name = "mirror",
-    version = "0.7.2",
+    version = "0.7.4",
     fullname = "Mirror for open source mirror site",
     description = "Mirror for open source mirror site to sync files",
     author = "Shang Yuanchun, Bob Gao",