re-enabled -Woverloaded-virtual

git-svn-id: svn://bind10.isc.org/svn/bind10/branches/parkinglot@731 e5f2f494-b856-4b98-b285-d166d9295462

configure.ac

@@ -19,11 +19,7 @@ AM_PATH_PYTHON([3.1])
 
 # default compiler warning settings
 if test "X$GCC" = "Xyes"; then
-#-Woverloaded-virtual will produce so many warnings.  Suppress them for rapid
-# prototyping, but we should soon fix the code, rather than ignoring the
-# warnings!!
-#CXXFLAGS="-g -Wall -Wwrite-strings -Woverloaded-virtual -Wno-sign-compare"
-CXXFLAGS="-g -Wall -Wwrite-strings -Wno-sign-compare"
+CXXFLAGS="-g -Wall -Wwrite-strings -Woverloaded-virtual -Wno-sign-compare"
 fi
 
 # produce PIC unless we disable shared libraries. need this for python bindings.