Mute Guetzli error logging
Mute Guetzli error logging

google/fuzzer-test-suite,dnoursi/fuzzer-test-suite,bshastry/fuzzer-test-suite,bshastry/fuzzer-test-suite,google/fuzzer-test-suite,dnoursi/fuzzer-test-suite,dnoursi/fuzzer-test-suite,dnoursi/fuzzer-test-suite,bshastry/fuzzer-test-suite,dnoursi/fuzzer-test-suite,google/fuzzer-test-suite