Update revisions.txt

Author: Federico Fissore

build/shared/revisions.txt

@@ -14,6 +14,7 @@ ARDUINO 1.6.5
 * Serial monitor stays opened during upload, disabled. Thanks @avishorp and @Wackerbarth
 * CLI: --get-pref can now be called without a pref name. If pref name is missing, IDE dumps all preferences
 * Holding SHIFT when hovering the save icon will trigger a "Save As"
+* Removed proxy settings from File > Preferences: IDE will use system settings
 * Tons of minor fixes
 
 [libraries]