Entering a pawn endgame is no more dangerous

A simplification of the 'dangerous' definition.

Seems neutral at reverse test at long TC

master vs patch
LLR: -2.96 (-2.94,2.94)
Total: 16974 W: 3122 L: 3139 D: 10713

bench: 4689029
Merge branch 'master' of https://github.com/mcostalba/Stockfish