Determine process at log-time, not startup-time.

This is because things like the fedmsg-hub are daemons, and will double-fork
into the background.  If we determine the process at startup time, that original
process is long dead by the time we get to the first log statement.

roles/fedmsg_base/templates/logging.py.j2

@@ -27,6 +27,9 @@ class ContextInjector(logging.Filter):
     """
 
     def filter(self, record):
+        current_process = ContextInjector.get_current_process()
+        current_hostname = socket.gethostname()
+
         record.host = current_hostname
         record.proc = current_process
         record.pid = current_process.pid
@@ -67,9 +70,6 @@ class ContextInjector(logging.Filter):
         return {'name': 'ContextInjector'}
 
 
-current_process = ContextInjector.get_current_process()
-current_hostname = socket.gethostname()
-
 hefty_format = """Message
 -------
 [%(asctime)s][%(name)10s %(levelname)7s]