Remove default keybind for range select (#12632)

Reason: accidental key presses, few use-cases.

builtin/settingtypes.txt

@@ -2122,7 +2122,7 @@ keymap_cmd_local (Command key) key .
 
 #    Key for toggling unlimited view range.
 #    See http://irrlicht.sourceforge.net/docu/namespaceirr.html#a54da2a0e231901735e3da1b0edf72eb3
-keymap_rangeselect (Range select key) key KEY_KEY_R
+keymap_rangeselect (Range select key) key
 
 #    Key for toggling flying.
 #    See http://irrlicht.sourceforge.net/docu/namespaceirr.html#a54da2a0e231901735e3da1b0edf72eb3

src/defaultsettings.cpp

@@ -87,7 +87,7 @@ void set_default_settings()
 	settings->setDefault("keymap_cmd_local", ".");
 	settings->setDefault("keymap_minimap", "KEY_KEY_V");
 	settings->setDefault("keymap_console", "KEY_F10");
-	settings->setDefault("keymap_rangeselect", "KEY_KEY_R");
+	settings->setDefault("keymap_rangeselect", "");
 	settings->setDefault("keymap_freemove", "KEY_KEY_K");
 	settings->setDefault("keymap_pitchmove", "KEY_KEY_P");
 	settings->setDefault("keymap_fastmove", "KEY_KEY_J");