[FIX]Refixed the issue of oe_sessions_effectiveusername storage in temp, used geteuid which returns effective user id.

bzr revid: msh@openerp.com-20130530090814-6uf0hs5j0223w985

addons/web/http.py

@@ -487,6 +487,10 @@ class DisableCacheMiddleware(object):
         return self.app(environ, start_wrapped)
 
 def session_path():
+    try:
+        import pwd
+        username = pwd.getpwuid(os.geteuid()).pw_name
+    except ImportError:
         try:
             username = getpass.getuser()
         except Exception: