added missing fittingwidget import

Author: klytje

src/sas/qtgui/Perspectives/Fitting/FittingWidget.py

@@ -39,6 +39,7 @@
 from sas.sascalc.fit import models
 from sas.sascalc.fit.BumpsFitting import BumpsFit as Fit
 from sas.system import HELP_SYSTEM
+from sas.system.user import find_plugins_dir
 
 TAB_MAGNETISM = 4
 TAB_POLY = 3