signtool.sh: add verbose logging to osslsigncode

In the issue mentioned below, we've been investigating a problem where
code signing _sometimes_ hangs on arm64, but not consistently. It seems
to hang somewhere around the osslsigncode.exe process. Let's add some
verbose logging there to see if it helps us in the debugging process
somehow...

Ref: git-for-windows/git#3107 (comment)
Signed-off-by: Dennis Ameling <dennis@dennisameling.com>

signtool.sh

@@ -26,6 +26,7 @@ type osslsigncode >/dev/null 2>&1 || {
 
 s () {
 	osslsigncode.exe sign \
+		-verbose \
 		-pkcs12 "$HOME/.sig/codesign.p12" \
 		-readpass "$HOME/.sig/codesign.pass" \
 		-ts http://timestamp.comodoca.com?td=sha256 \