ATLAS-2971: Atlas fails to start if there is a empty pid file

distro/src/bin/atlas_start.py

@@ -101,7 +101,7 @@ def main():
        pf = file(atlas_pid_file, 'r')
        pid = pf.read().strip()
        pf.close()
-
+       if pid != "":
            if mc.exist_pid((int)(pid)):
                if is_setup:
                    print "Cannot run setup when server is running."