sysutils/synergy: Correct version confusion: current version is 1.x.x, not 2.x.x

Therefore sysutils/synergy-1 is removed, and sysutils/synergy PORTEPOCH is bumped because the prevuous commit went backwards 2.x.x -> 1.x.x

Reference: https://github.com/symless/synergy-core/issues/6850#issuecomment-732045154

Reported by: Aleksander Matveev <timon@timon.net.nz>