Stabilization of unittests

tests/test_error_engine.py

@@ -22,7 +22,7 @@ import sys
 import unittest
 
 sys.path.insert(0, os.path.dirname(os.path.abspath(__file__)))
-from _testutils import bootstrap, set_dbms
+from _testutils import bootstrap, set_dbms, reset_dbms
 bootstrap()
 
 from lib.core.data import conf, kb
@@ -111,3 +111,7 @@ class TestOneShotErrorUse(unittest.TestCase):
 
 if __name__ == "__main__":
     unittest.main(verbosity=2)
+
+
+def tearDownModule():
+    reset_dbms()   # clear any DBMS forced via set_dbms() so it can't leak into later test modules