fix typo in ProtoMessage.toString()

[etan-status]

The debugutils.nim file doesn't compile due to typo in withValue. Fix it for now.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 82.78%. Comparing base (e9b4561) to head (8976b6b).

Additional details and impacted files

@@             Coverage Diff              @@
##           unstable    #1033      +/-   ##
============================================
+ Coverage     82.75%   82.78%   +0.03%     
============================================
  Files            91       91              
  Lines         15616    15616              
============================================
+ Hits          12923    12928       +5     
+ Misses         2693     2688       -5     

see 3 files with indirect coverage changes

[etan-status]

• increase tolerance of simple heartbeat test #1034