startup: show an error message when argument of --operatingdir is invalid

Move the initialization of the operating directory to after the
initialization of the screen, so that the above error can be shown.

This fixes the first part of https://savannah.gnu.org/bugs/?47798.

src/files.c

@@ -1591,6 +1591,7 @@ void init_operating_dir(void)
     /* If get_full_path() failed or the operating directory is
      * inaccessible, unset operating_dir. */
     if (full_operating_dir == NULL || chdir(full_operating_dir) == -1) {
+	statusline(ALERT, _("Not a valid directory: %s"), operating_dir);
 	free(full_operating_dir);
 	full_operating_dir = NULL;
 	free(operating_dir);

src/nano.c

@@ -2422,12 +2422,6 @@ int main(int argc, char **argv)
 	init_backup_dir();
 #endif
 
-#ifndef DISABLE_OPERATINGDIR
-    /* Set up the operating directory.  This entails chdir()ing there,
-     * so that file reads and writes will be based there. */
-    init_operating_dir();
-#endif
-
 #ifndef DISABLE_JUSTIFY
     /* If punct wasn't specified, set its default value. */
     if (punct == NULL)
@@ -2559,6 +2553,12 @@ int main(int argc, char **argv)
 	controlright = key_defined(keyvalue);
 #endif
 
+#ifndef DISABLE_OPERATINGDIR
+    /* Set up the operating directory.  This entails chdir()ing there,
+     * so that file reads and writes will be based there. */
+    init_operating_dir();
+#endif
+
 #ifdef DEBUG
     fprintf(stderr, "Main: open file\n");
 #endif