Add compilation options -DENABLE_TESTS=ON cause project compile fail

[zzl133]

Add compilation options such as：cmake -DENABLE_TESTS=ON .. This command causes compilation to fail，As mentioned in the pingcap Developer Forum, grpc is compiled with dynamic libraries. The old version of clien-c can be compiled and used temporarily, but the latest version cannot. Moreover, we recommend using static libraries.Please fix it as soon as possible. Thank you