Removed unneeded update instruction
Removed unneeded update instruction

Since Docker image is up-to-date,
updating packages and repositories is not necessary.
google/fuzzer-test-suite,dnoursi/fuzzer-test-suite,google/fuzzer-test-suite,dnoursi/fuzzer-test-suite,bshastry/fuzzer-test-suite,dnoursi/fuzzer-test-suite,bshastry/fuzzer-test-suite,dnoursi/fuzzer-test-suite,google/fuzzer-test-suite,dnoursi/fuzzer-test-suite,bshastry/fuzzer-test-suite