Fix KDB export group creation

This fixes a silly variable change in commit d9dc79d.
It also fixes the path segments search and creation.

pass_import/formats/kdbx.py

@@ -164,10 +164,13 @@ def insert(self, entry):
         group = os.path.dirname(path)
 
         root_group = self.keepass.root_group
-        kpgroup = self.keepass.find_groups(path=os.path.split(path))
+        kpgroup = self.keepass.find_groups(path=os.path.split(group))
         if not kpgroup:
             for grp in os.path.split(group):
-                kpgroup = self.keepass.find_groups(path=grp)
+                # os.path.split creates an empty segment when there is nothing to split, just ignore it
+                if grp == '':
+                    continue
+                kpgroup = self.keepass.find_groups(group=root_group, name=grp, first=True)
                 if not kpgroup:
                     kpgroup = self.keepass.add_group(root_group, grp)
                 root_group = kpgroup