graphics/s2: Remove GFLAGS and GLOG options

• Bump PORTREVISION for dependency change

They are replaced by abseil-cpp.

Reference: https://github.com/google/s2geometry/commit/d1843025b675a06f67c5f5e3eebc9380d7a52e3f

		https://github.com/google/s2geometry/commit/418c55893f6123b90f2768ed2ec9f5f47fa512de