[FIX] server: support psutils >= 4.0

In version 3, process.memory_info() returns only rss and vms
In version 4, it now returns rss, vms, shared, text, lib, data and dirty
Automatic unpacking is no longer possible in 4.0

Fixes #11052, Closes #11459

openerp/service/server.py

@@ -47,7 +47,8 @@ SLEEP_INTERVAL = 60     # 1 min
 def memory_info(process):
     """ psutil < 2.0 does not have memory_info, >= 3.0 does not have
     get_memory_info """
-    return (getattr(process, 'memory_info', None) or process.get_memory_info)()
+    pmem = (getattr(process, 'memory_info', None) or process.get_memory_info)()
+    return (pmem.rss, pmem.vms)
 
 #----------------------------------------------------------
 # Werkzeug WSGI servers patched