git-gui: Help identify aspell version on Windows too

On windows, git gui fails to correctly extract the aspell version
(experienced with aspell version 0.50.3) due to scilent white space at
the end of the version string.  Trim the obtained version string to
work around this.

Signed-off-by: Gustaf Hendeby <hendeby@isy.liu.se>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

lib/spellcheck.tcl

@@ -80,7 +80,7 @@ method _connect {pipe_fd} {
 		error_popup [strcat [mc "Unrecognized spell checker"] ":\n\n$s_version"]
 		return
 	}
-	set s_version [string range $s_version 5 end]
+	set s_version [string range [string trim $s_version] 5 end]
 	regexp \
 		{International Ispell Version .* \(but really (Aspell .*?)\)$} \
 		$s_version _junk s_version