Add percent-encoding to CHANGELOG.

CHANGELOG.md

@@ -27,6 +27,7 @@
 - Fixed the QSO index used in the Gtk.ListStore. Just before a QSO is added with add_record it was assumed that it's index would be max(rowid)+1, which is not always the case. This led to inconsistencies between the Gtk.ListStore and the database. Indices used in the Gtk.ListStore are now obtained directly from the database after insertion.
 - Direction of sorting.
 - IOTA data retrieval when looking up callsigns using hamqth.com.
+- Use percent-encoding when connecting to a callsign database.
 
 ## [0.3] - 2016-05-28
 ### Added