Makefile: change default hostname to max80.local

If max80 is discovered via mDNS, it will appear as "max80.local"; it
makes sense to make that the default hostname for uploads as .local is
often not part of the default search prefixes.

Makefile

@@ -7,7 +7,7 @@ REVISIONS := v1 v2 bypass
 GIT_DIR   ?= .git
 TEMP      ?= /tmp
 
-MAX80_IP  ?= max80
+MAX80_IP  ?= max80.local
 
 CURL	   = curl
 PERL	   = perl