mid: Support Message-ID

'b4 --add-message-id' uses 'Message-ID', similar to what is in the email
headers. While patchew uses 'Message-ID'.

Allow both, or any variation.

Signed-off-by: Matthieu Baerts (NGI0) <[email protected]>

Author: matttbe

entrypoint.sh

@@ -202,7 +202,7 @@ always_build() {
 
 get_mid() { local mid
 	mid=$(git log -1 --format="format:%b" | \
-		grep "^Message-Id: " | \
+		grep -i "^Message-Id: " | \
 		tail -n1 | \
 		awk '{print $2}')