Fix capitalization on the "Update add-ons" button

(Although I'd honestly just uncapitalize everything.)

data/gui/default/window/addon_connect.cfg

@@ -134,8 +134,8 @@
 
 #									tooltip = "Update locally installed addons."
 
-									size_text = _ "Update add-ons"
-									label = _ "Update add-ons"
+									size_text = _ "Update Add-ons"
+									label = _ "Update Add-ons"
 
 									# we define the return value manually instead of being
 									# linked to the id. Not sure whether that's the best

utils/pofix.py

@@ -3782,6 +3782,7 @@ stringfixes = {
 
 # Fix capitalization
 ("Lava chasm", "Lava Chasm"),
+("Update add-ons", "Update Add-ons"),
 ),
 
 "wesnoth-manual" : (