git-gui: Remove space from the end of aspell's reply before processing

git-gui: Remove space from the end of aspell's reply before processing

When git gui processes a reply from aspell it explicitly ignores an empty
line. The Windows version of aspell, however, terminates lines with CRLF,
but TCL's 'gets' does not remove CR, hence, a "visibly" empty line was not
actually recognized as empty. With this change we explicitly trim off
whitespace before the line is further processed.

Signed-off-by: Johannes Sixt <redacted>
Signed-off-by: Shawn O. Pearce <redacted>