Terran upgrade: RESEARCH_MAGFIELDLAUNCHERS

RESEARCH_MAGFIELDLAUNCHERS is in the ABILITY_ID list as ID 766.
This appears to be an older upgrade that is no longer in the current game.
However, ID 766 is actually now RESEARCH_SMARTSERVOS, an entirely different upgrade.

I am unclear if this is a documentation error (the ID was never 766 and someone input it wrong), or if the actual game client actually re-used the ID and changed it when they implemented the "Smart Servos" upgrade. I do not know how to find this answer.

I added RESEARCH_SMARTSERVOS in PR https://github.com/Blizzard/s2client-api/issues/228 but left RESEARCH_MAGFIELDLAUNCHERS with the same ID so as not to break anyone who had used that ID in their code.