PrismSettings: resave to the same file used for loading

When PrismSettings loads a settings file from a previous version,
in loadSettingsFile(File) it resaves the file to add the settings
of the current version.

Previously, for resave it would write to the default location, no
matter if the settings file location passed to loadSettingsFile
pointed to another file (e.g., due to loading the settings on the
command-line PRISM with -settings ...).

Now, we resave to the same file as that used for loading.

prism/src/prism/PrismSettings.java

@@ -853,7 +853,7 @@ public class PrismSettings implements Observer
 		// If necessary, resave the preferences file
 		if (resaveNeeded) {
 			try {
-				saveSettingsFile();
+				saveSettingsFile(file);
 			}
 			catch (PrismException e) {
 			}