prosody: fix restart loop on rolling deployment

prosody/rootfs/defaults/prosody.cfg.lua

@@ -93,7 +93,7 @@ allow_registration = false;
 
 daemonize = false;
 
-pidfile = "/config/data/prosody.pid";
+pidfile = "/tmp/prosody.pid";
 
 -- Force clients to use encrypted connections? This option will
 -- prevent clients from authenticating unless they are using encryption.