Fix unnecessary reencryptions on macOS

POSIX sed doesn't support \+ in BREs which causes the regex that
extracts a file's current keys to return nothing, meaning that files
are unnecessarily reencrypted.
This converts the regex in question to use ERE.

https://git.zx2c4.com/password-store/commit/?id=04cd3023f48cd203f6c0193e57a427226e8b431c
--- src/password-store.sh.orig
+++ src/password-store.sh
@@ -129,7 +129,7 @@ reencrypt_path() {
 			done
 			gpg_keys="$($GPG $PASSWORD_STORE_GPG_OPTS --list-keys --with-colons "${GPG_RECIPIENTS[@]}" | sed -n 's/^sub:[^idr:]*:[^:]*:[^:]*:\([^:]*\):[^:]*:[^:]*:[^:]*:[^:]*:[^:]*:[^:]*:[a-zA-Z]*e[a-zA-Z]*:.*/\1/p' | LC_ALL=C sort -u)"
 		fi
-		current_keys="$(LC_ALL=C $GPG $PASSWORD_STORE_GPG_OPTS -v --no-secmem-warning --no-permission-warning --decrypt --list-only --keyid-format long "$passfile" 2>&1 | sed -n 's/^gpg: public key is \([A-F0-9]\+\)$/\1/p' | LC_ALL=C sort -u)"
+		current_keys="$(LC_ALL=C $GPG $PASSWORD_STORE_GPG_OPTS -v --no-secmem-warning --no-permission-warning --decrypt --list-only --keyid-format long "$passfile" 2>&1 | sed -nE 's/^gpg: public key is ([A-F0-9]+)$/\1/p' | LC_ALL=C sort -u)"
 
 		if [[ $gpg_keys != "$current_keys" ]]; then
 			echo "$passfile_display: reencrypting to ${gpg_keys//$'\n'/ }"