Revert "protobuf.pc.in does not reflect CXXFLAGS"
Revert "protobuf.pc.in does not reflect CXXFLAGS"

This reverts commit a7180caf19ae150d9a3f9724600b0eed4b5da830.

google/protobuf,google/protobuf,google/protobuf,google/protobuf,google/protobuf,google/protobuf,google/protobuf,google/protobuf,google/protobuf,google/protobuf,google/protobuf