git-gui: Remove invalid DM state.

The DM state cannot really happen.  Its implying that the file has
been deleted in the index, but the file in the working directory has
been modified relative to the file in the index.  This is complete
nonsense, the file doesn't exist in the index for it to be different
against!

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

git-gui.sh

@@ -1114,8 +1114,7 @@ proc commit_committree {fd_wt curHEAD msg} {
 		AM -
 		AD -
 		MM -
-		MD -
-		DM {
+		MD {
 			set file_states($path) [list \
 				_[string index $m 1] \
 				[lindex $s 1] \
@@ -2872,8 +2871,7 @@ proc toggle_or_diff {w x y} {
 		A_ -
 		M_ -
 		D_ -
-		DO -
-		DM {
+		DO {
 			update_indexinfo \
 				"Removing [short_path $path] from commit" \
 				[list $path] \