use default implementation of showInterpreterPreferencePage()

plugins/org.eclipse.dltk.python.debug.ui/src/org/eclipse/dltk/python/internal/debug/ui/interpreters/PythonInterpreterComboBlock.java

diff --git a/plugins/org.eclipse.dltk.python.debug.ui/src/org/eclipse/dltk/python/internal/debug/ui/interpreters/PythonInterpreterComboBlock.java b/plugins/org.eclipse.dltk.python.debug.ui/src/org/eclipse/dltk/python/internal/debug/ui/interpreters/PythonInterpreterComboBlock.java
index 3d5f842..b605464 100644
--- a/plugins/org.eclipse.dltk.python.debug.ui/src/org/eclipse/dltk/python/internal/debug/ui/interpreters/PythonInterpreterComboBlock.java
+++ b/plugins/org.eclipse.dltk.python.debug.ui/src/org/eclipse/dltk/python/internal/debug/ui/interpreters/PythonInterpreterComboBlock.java
@@ -19,10 +19,6 @@
 		super(tab);
 	}
 
-	protected void showInterpreterPreferencePage() {
-		showPrefPage(PythonInterpreterPreferencePage.PAGE_ID);
-	}
-
 	protected String getCurrentLanguageNature() {
 		return PythonNature.NATURE_ID;
 	}