Remove obsolete os.system call to git describe

pwman/__init__.py

@@ -26,7 +26,6 @@ try:
     version = pkg_resources.get_distribution('pwman3').version
 except pkg_resources.DistributionNotFound:
     version = "0.5-dev"
-    os.system('git describe')
 
 website = "http://github.com/pwman3/pwman3"
 author = "Oz Nahum"