Drop duplicated chainparamsconstants.cpp

Summary:
The src/chainparamsconstants.cpp has bee superseded by
src/netwoks/abc/chainparamsconstants.cpp but not removed.

Test Plan:

ninja all check-all

Reviewers: #bitcoin_abc, PiRK

Reviewed By: #bitcoin_abc, PiRK

Differential Revision: https://reviews.bitcoinabc.org/D9339