increase lufi size limit from 2G to 3G

pica-lufi/lufi.conf

@@ -60,7 +60,7 @@
     # Max file size, in octets
     # You can write it 100*1024*1024
     # optional, no default
-    max_file_size     => 2048*1024*1024,
+    max_file_size     => 3072*1024*1024,
 
     # If you want to have piwik statistics, provide a piwik image tracker
     # Only the image tracker is allowed, no javascript