[BUG] repeatedly executing a command when logging into the portal

[SL-69]

Describe the bug
sometimes when colliding with a horizontal portal, the command can be executed 2 or more times. The same thing happens with a cooldown.

To Reproduce
Steps to reproduce the bug:

1. portal.yml - https://pastebin.com/qR7Qufs7
2. have a run or don’t run and jump from a sufficient height at an angle (difficult to reproduce)
3. wow! command executed two or more times. in addition, if there is an empty area under the portal, then you can spam cooldown messages by jumping

Expected behavior
Execute the command 1 time. delay messages about cooldown

Server Information (Please fill in the information below):

• Version: paper 1.12.2 last build
• Plugins: AdvancedBan, ajLeaderboards, ajParkour, antiRedstoneClock, ArmorStandTools, AuctionHouse, BannerMaker, BKCommonLib, ChatEx, ChestCommands, ClearLag, CombatTagPlus, CompatNoCheatPlus, DecentHolograms, EasySetSpawn, Essentials, EssentialsDiscord, FastAsyncWorldEdit, FunctionalClans, GrimAC, IllegalStack, IRandomTeleport, LightCleaner, Log4jFix, LuckPerms, MoneyFromMobs, NBTAPI, NoCheatPlus, Orebfuscator, PlaceholderAPI, ProtectionStones, ProtocolLib, ResourcePackDownloader, SimplePortals, SimpleRename, SkinsRestorer, TAB, UltimateServerProtector, Vault, ViaVersion,
  WorldEdit, WorldGuard, ZNPCsPlus