removed obsolete setting tweaks: build -s already sets output correctly

--- a/Admin/mira.py	Wed Dec 19 11:13:37 2012 +0100
+++ b/Admin/mira.py	Wed Dec 19 12:12:32 2012 +0100
@@ -23,9 +23,6 @@
     # patch settings
     extra_settings = '''
 ISABELLE_HOME_USER="$ISABELLE_HOME/home_user"
-ISABELLE_OUTPUT="$ISABELLE_HOME/heaps"
-ISABELLE_BROWSER_INFO="$ISABELLE_HOME/browser_info"
-ISABELLE_PATH="$ISABELLE_OUTPUT"
 
 Z3_NON_COMMERCIAL="yes"