New comment by Eluminae on mblaze repository

https://github.com/leahneukirchen/mblaze/issues/202#issuecomment-771617509

Comment:
Something like this seems enough to me

```
diff --git a/bin/mverify b/bin/mverify
index 1624d49..21e7e24 100755
--- a/bin/mverify
+++ b/bin/mverify
@@ -11,6 +11,13 @@ fi

 [ "$#" -eq 0 ] && set -- .

+if mshow -t "$1" | grep -q "multipart/encrypted"; then
+       tmp=$(mktemp -t mgpg.XXXXXX)
+       trap "rm -f '$tmp'" INT TERM EXIT
+       mshow -r "$1" | "$GPG" -d > "$tmp"
+       set -- "$tmp"
+fi
+
 mshow -t "$1" | DOS2UNIX='/^M$/!s/$/^M/' awk -v "msg=$1" '
 { match($0, "^ *"); indent = RLENGTH }
 $2 == "text/plain" { plain++ }
```

edit: we should add some `-n` args to some `mshow` to avoid linking the tmp file