test-cases: be sure the test-files always written with new-line at end

fail2ban/tests/fail2banclienttestcase.py

@@ -126,7 +126,7 @@ def _out_file(fn, handle=logSys.debug):
 
 def _write_file(fn, mode, *lines):
 	f = open(fn, mode)
-	f.write('\n'.join(lines))
+	f.write('\n'.join(lines)+('\n' if lines else ''))
 	f.close()
 
 def _read_file(fn):