Fix a bug in field-map handling.

* libmailutils/cfg/driver.c (parse_mapping): Fix expected value type.
* libmu_auth/sql.c (get_field): Remove left-over mu_assoc_ref call
(see 622bc770).

@@ -72,7 +72,7 @@ is the same as for the global section described above, e.g.:
 
 If the "tls" section is absent, but "tls-mode" is specified and it's
 value is anything but "no", the settings from the global "tls" section
-will be used.  Im this case, it is an error if the global "tls"
+will be used.  In this case, it is an error if the global "tls"
 section is not defined.
 
 

@@ -617,10 +617,15 @@ static int
 parse_mapping (void *item, void *data)
 {
   struct mapping_closure *clos = data;
-  char *str = item;
+  struct mu_config_value *cval = item;
+  char const *str;
   size_t len;
   char *key, *val;
   int rc;
+
+  if (mu_cfg_assert_value_type (cval, MU_CFG_STRING))
+    return 1;
+  str = cval->v.string;
   
   len = strcspn (str, "=");
   if (str[len] == 0)

@@ -214,20 +214,23 @@ mu_sql_expand_query (const char *query, const char *ustr)
 static int
 get_field (mu_sql_connection_t conn, const char *id, char **ret, int mandatory)
 {
-  const char **name = mu_assoc_ref (mu_sql_module_config.field_map, id);
-  int rc = mu_sql_get_field (conn, 0, name ? *name : id, ret);
+  int rc;
+  const char *name = mu_assoc_get (mu_sql_module_config.field_map, id);
+  if (!name)
+    name = id;
+  rc = mu_sql_get_field (conn, 0, name, ret);
   if (rc)
     {
       if (mandatory || rc != MU_ERR_NOENT)
 	mu_error (_("cannot get SQL field `%s' (`%s'): %s"),
-		  id, name ? *name : id, mu_strerror (rc));
+		  id, name, mu_strerror (rc));
     }
   else if (!*ret)
     {
       if (mandatory)
 	{
 	  mu_error (_("SQL field `%s' (`%s') has NULL value"),
-		    id, name ? *name : id);
+		    id, name);
 	  rc = MU_ERR_READ;
 	}
       else