mysql: Don't ask for password if .mysql.hash exists

mysql/debian/config

@@ -2,10 +2,12 @@
 
 . /usr/share/debconf/confmodule
 
-while [ -z "$RET" ] ; do
-  db_input high symbiosis-mysql/admin_password || true
-  db_go
-  db_get symbiosis-mysql/admin_password
-done
+if [ ! -e /etc/first-boot.d/.mysql.hash ] ; then
+  while [ -z "$RET" ] ; do
+    db_input high symbiosis-mysql/admin_password || true
+    db_go
+    db_get symbiosis-mysql/admin_password
+  done
+fi
 
 exit 0

test/internal-test.d/conf-stretch/debconf-preseed

@@ -7,7 +7,7 @@ mysql-server-5.5	mysql-server/root_password	password	semiconscious malpractice
 # Repeat password for the MySQL "root" user:
 mysql-server-5.5	mysql-server/root_password_again	password	semiconscious malpractice
 # Set password for the MySQL "admin" user for phpMyAdmin access:
-symbiosis-mysql	symbiosis-mysql/admin_password	password	semiconscious malpractice
+symbiosis-mysql		symbiosis-mysql/admin_password		password	semiconscious malpractice
 # Password of the database's administrative user:
 phpmyadmin	phpmyadmin/mysql/admin-pass	 password	semiconscious malpractice
 # Password of the database's administrative user: