cmake: fix protobuf library name

Protocol Buffers library has a name `protobufd` when CMAKE_BUILD_TYPE is
equal to "Debug". In other cases the name is `protobuf`. The patch fixes
the library name.

Follows up commit b11072a6 ("cmake: add dependencies for LuaJIT and
SQL fuzzers").

Follows up #4823

NO_CHANGELOG=build
NO_DOC=build
NO_TEST=build

(cherry picked from commit c0d8cb54)