recipetool: Fix errors with meta-poky bbappend

When a new base-files bbappend was added to meta-poky, it causes selftest
failures. Whilst this isn't ideal, workaround that issue for now since
the append is being added for security visibility and changing the tests
to support this more generically looks invasive.

(From OE-Core rev: 7cf85204f0943bf741ffce5c4105340197c714df)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/lib/oeqa/selftest/cases/recipetool.py

@@ -48,6 +48,8 @@ class RecipetoolBase(devtool.DevtoolTestCase):
         self.testfile = os.path.join(self.tempdir, 'testfile')
         with open(self.testfile, 'w') as f:
             f.write('Test file\n')
+        config = 'BBMASK += "meta-poky/recipes-core/base-files/base-files_%.bbappend"\n'
+        self.append_config(config)
 
     def tearDownLocal(self):
         runCmd('rm -rf %s/recipes-*' % self.templayerdir)