imagemagick/encoder_wpg_fuzzer: Use-of-uninitialized-value in ConstrainColormapIndex

Project: https://github.com/imagemagick/imagemagick.git Detailed report: https://oss-fuzz.com/testcase?key=5521019725938688 Project: imagemagick Fuzzer: libFuzzerimagemagickencoderwpgfuzzer Fuzz target binary: encoderwpgfuzzer Job Type: libfuzzermsanimagemagick Platform Id: linux Crash Type:...