Use Jessie instead of Ubuntu Dockerfile for GCC-4.8 tests
diff --git a/tools/run_tests/run_tests.py b/tools/run_tests/run_tests.py
index 05f819b..8f043f9 100755
--- a/tools/run_tests/run_tests.py
+++ b/tools/run_tests/run_tests.py
@@ -333,7 +333,7 @@
elif compiler == 'gcc4.6':
return ('wheezy', self._gcc_make_options(version_suffix='-4.6'))
elif compiler == 'gcc4.8':
- return ('ubuntu1604', self._gcc_make_options(version_suffix='-4.8'))
+ return ('jessie', self._gcc_make_options(version_suffix='-4.8'))
elif compiler == 'gcc5.3':
return ('ubuntu1604', [])
elif compiler == 'clang3.4':