git-gui: Fix a loose/lose mistake

Acked-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Beat Bolli <bbolli@ewanet.ch>
Signed-off-by: Pat Thoyts <patthoyts@users.sourceforge.net>

lib/commit.tcl

@@ -268,7 +268,7 @@ proc commit_commitmsg {curHEAD msg_p} {
 	    && 	[is_config_true gui.warndetachedcommit]} {
 		set msg [mc "You are about to commit on a detached head.\
 This is a potentially dangerous thing to do because if you switch\
-to another branch you will loose your changes and it can be difficult\
+to another branch you will lose your changes and it can be difficult\
 to retrieve them later from the reflog. You should probably cancel this\
 commit and create a new branch to continue.\n\
 \n\