fiji_scripts: remove unnecessary (and wrong) hash ref initialization

FIJI/Settings.pm

@@ -127,9 +127,7 @@ sub read_settingsfile {
     return undef;
   }
   my $fiji_settings_ref;
-  if (!defined($existing_settings)) {
-    $fiji_settings_ref = \{};
-  } else {
+  if (defined($existing_settings)) {
     $fiji_settings_ref = $existing_settings;
     if (!blessed($fiji_settings_ref) || !$fiji_settings_ref->isa("FIJI::Settings")) {
       $logger->error("Given settings are not of type FIJI::Settings.");