fix grandpa time

[turuslan]

Referenced issues

• grandpa: increase gossip duration to 1s paritytech/polkadot#781
• Double grandpa gossip duration for Kusama and test networks paritytech/polkadot#5448
• Hybrid network of kagome-substrate peers lags with finalization #1218

Description of the Change

• update const
• fix difference sign

Benefits

Fix finalization.

Possible Drawbacks

Usage Examples or Tests

Alternate Designs

[igor-egorov]

Looks promising

[codecov]

Codecov Report

Merging #1346 (cb91b14) into master (c48739c) will increase coverage by 0.01%.
The diff coverage is 45.00%.

❗ Current head cb91b14 differs from pull request most recent head 48a5e96. Consider uploading reports for the commit 48a5e96 to get more accurate results

@@            Coverage Diff             @@
##           master    #1346      +/-   ##
==========================================
+ Coverage   24.38%   24.40%   +0.01%     
==========================================
  Files         619      619              
  Lines       23021    23036      +15     
  Branches    12011    12019       +8     
==========================================
+ Hits         5614     5621       +7     
- Misses      12225    12226       +1     
- Partials     5182     5189       +7     

Impacted Files	Coverage Δ
core/consensus/babe/impl/babe_impl.cpp	14.02% <0.00%> (-0.03%)	⬇️
core/consensus/grandpa/impl/grandpa_impl.hpp	100.00% <ø> (ø)
core/consensus/grandpa/impl/voting_round_impl.cpp	24.05% <0.00%> (ø)
core/injector/application_injector.cpp	32.12% <ø> (ø)
core/consensus/grandpa/impl/grandpa_impl.cpp	3.05% <50.00%> (+0.40%)	⬆️
core/application/chain_spec.hpp	63.63% <60.00%> (-36.37%)	⬇️

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