gitk: Prevent the text pane from becoming editable
gitk: Prevent the text pane from becoming editable

When setting the "Patch/Tree" radio buttons to "Tree" and
clicking on a file to display it, the text pane would
accidentally become editable (because of the early return
in getblobline).

Signed-off-by: Stefan Haller <eb0877843acc39f8ef6f7269937dee931c372d23@haller-berlin.de>
Signed-off-by: Paul Mackerras <19a0ba370c443ba08d20b5061586430ab449ee8c@samba.org>

destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git