DceRpc fix register_dcerpc_interface duplication

[gpotter2]

• there was leftover code from when I thought versions didn't matter

[codecov]

Codecov Report

Attention: Patch coverage is 75.00000% with 1 line in your changes missing coverage. Please review.

Project coverage is 82.11%. Comparing base (53b9cce) to head (538a4e6).
Report is 1 commits behind head on master.

Files with missing lines	Patch %	Lines
scapy/layers/dcerpc.py	75.00%	1 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #4672   +/-   ##
=======================================
  Coverage   82.11%   82.11%           
=======================================
  Files         359      359           
  Lines       86576    86573    -3     
=======================================
+ Hits        71088    71093    +5     
+ Misses      15488    15480    -8     

Files with missing lines	Coverage Δ
scapy/layers/dcerpc.py	91.42% <75.00%> (+0.24%)	⬆️

... and 10 files with indirect coverage changes