Bug fix in PRISM API: modelCheck(String) should use ModelInfo for parsing.

Does not show up in normal usage of PRISM currently (CL/GUI).

prism/src/prism/Prism.java

@@ -2850,7 +2850,7 @@ public class Prism extends PrismComponent implements PrismSettingsListener
 	 */
 	public Result modelCheck(String propertyString) throws PrismException
 	{
-		PropertiesFile propertiesFile = parsePropertiesString(currentModelGenerator, propertyString);
+		PropertiesFile propertiesFile = parsePropertiesString(currentModelInfo, propertyString);
 		if (propertiesFile.getNumProperties() != 1) {
 			throw new PrismException("There should be exactly one property to check (there are " + propertiesFile.getNumProperties() + ")");
 		}