oeqa/runtime/buildcpio: Use our own mirror for source

We see occasional network glitches which break this test. Use our own
mirror (which has a .gz instead of .bz2) to avoid the errors, we're not
trying to test network connectivity.

(From OE-Core rev: 038d7270aef0cccf87d50a117160c58261beb9b9)

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

meta/lib/oeqa/runtime/cases/buildcpio.py

@@ -9,8 +9,7 @@ class BuildCpioTest(OERuntimeTestCase):
 
     @classmethod
     def setUpClass(cls):
-        uri = 'https://ftp.gnu.org/gnu/cpio'
-        uri = '%s/cpio-2.12.tar.bz2' % uri
+        uri = 'https://downloads.yoctoproject.org/mirror/sources/cpio-2.12.tar.gz'
         cls.project = TargetBuildProject(cls.tc.target,
                                          uri,
                                          dl_dir = cls.tc.td['DL_DIR'])