[tools] remove .sconsign.dblite when scons clean.
fixed py2 <==> py3 ValueError : unsupported pickle protocol: x
@@ -880,6 +880,7 @@ def EndBuilding(target, program = None):
Clean(target, 'cconfig.h')
Clean(target, 'rtua.py')
Clean(target, 'rtua.pyc')
+ Clean(target, '.sconsign.dblite')
if GetOption('target'):
GenTargetProject(program)
