Add debugging switch to fetch pks

debugging.fs

@@ -86,6 +86,7 @@ debug: deprecated( \ deprecated stuff
 debug: unhandled( \ unhandled commands
 debug: syncfile( \ synchronous file operations
 debug: newvault( \ new style vault keys
+debug: pks( \ fetch pks
 
 -db profile( \ don't profile by default )
 +db ipv6( \ ipv6 should be on by default )

msg.fs

@@ -1317,7 +1317,7 @@ previous
     reset-time
     msg-group-o >o msg:?otr msg:-otr o> >r
     [: cells >r msg-log@ { log u } u r> - 0 max { u' }
-      log u ?scan-pks  ?fetch-pks
+      pks( log u ?scan-pks  ?fetch-pks )
       log u' ?search-lock
       log u u' /string bounds ?DO
 	  I log - cell/ to log#