mail: Fix checkmail script password bugging

Fixed script to only ask for password once before understanding that the
user does not want to provide it.

Since gpg seems to not differentiate between a *wrongly* entered
password and one entered not at all, we have to assume the user canceled
the password prompt and not bug him again until the next time the script
is invoked.
It will, however, at least notify the user that the process is aborted
in a quick notification message, so that if it was done on accident the
user will still know what's up.

mail/.local/bin/mail-check

@@ -68,17 +68,27 @@ checkonline() {
 checkwarnuser() {
     agt=$(gpg2 --decrypt --no-tty --quiet --no-verbose --for-your-eyes-only --pinentry-mode cancel "$PASSWORD_FILE" 2>&1)
     if echo "$agt" | grep -qE 'No secret key'; then
-    notify "Mail: Password phrase needed!"
+        notify "Mail" "Password phrase needed!"
         sleep 2.5
     fi
 }
 
+enablegpgagent() {
+    ## get password from user
+    agt=$(gpg2 --decrypt --no-tty --quiet --no-verbose --for-your-eyes-only --pinentry-mode ask "$PASSWORD_FILE" 2>&1)
+    ## exit program after first failed attempt
+    if echo "$agt" | grep -qE 'decryption failed'; then
+        notify "Mail" "Process aborted."
+        exit 1
+    fi
+}
+
 # send out a notification on new mail, to libnotify and stdout
 notifymail() {
     [ "${MBSYNC_NOTIFY:-1}" -eq 0 ] && return
 
     if [ "${HASMAIL:-0}" -gt 0 ]; then
-    notify "($HASMAIL) new mail"
+        notify "Mail" "New Mail ($HASMAIL)"
     fi
 }
 
@@ -100,6 +110,8 @@ fi
 main() {
     checkwarnuser
 
+    enablegpgagent
+
     prehook
 
     tries=0