Make grep in Cygwin path-stripping code case-sensitive for consistency

The previous "case" check already is case-sensitive, so there is no point
in making grep case-insensitive.

Signed-off-by: Sebastian Schuberth <sschuberth@gmail.com>

etc/profile

@@ -24,7 +24,7 @@ fi
 # strip out cygwin paths from PATH
 case "$PATH" in
 */cygwin/*)
-	export PATH=$(p=$(echo $PATH | tr ":" "\n" | grep -vi "/cygwin/" | tr "\n" ":"); echo ${p%:})
+	export PATH=$(p=$(echo $PATH | tr ":" "\n" | grep -v "/cygwin/" | tr "\n" ":"); echo ${p%:})
 	;;
 esac