bitbake: lib: remove unused imports

removed unused imports which made the code harder to read, and slightly
but less efficient

(Bitbake rev: 4367692a932ac135c5aa4f9f2a4e4f0150f76697)

Signed-off-by: Frazer Clews <frazer.clews@codethink.co.uk>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/lib/toaster/bldcontrol/models.py

@@ -4,9 +4,8 @@
 
 from __future__ import unicode_literals
 from django.db import models
-from django.core.validators import MaxValueValidator, MinValueValidator
 from django.utils.encoding import force_text
-from orm.models import Project, ProjectLayer, ProjectVariable, ProjectTarget, Build, Layer_Version
+from orm.models import Project, Build, Layer_Version
 
 import logging
 logger = logging.getLogger("toaster")