As reported to msysGit (bug #340) it is possible to get some very
long error messages when updating the index. The use of a label to
display this prevents scrolling the output. This patch replaces the
label with a scrollable text widget configured to look like a label.
Signed-off-by: Pat Thoyts <patthoyts@users.sourceforge.net> Signed-off-by: Shawn O. Pearce <spearce@spearce.org>