Don't apply CTT fixes if RP-0 is loaded.

RP-0, a career mode for the RealismOverhaul universe with support for DMagic
Orbital Science, uses the CTT, but sets its own tech positions. While it would
be great if we could just do an `:AFTER[DMagic]` to do this, we can't do that
on MM stanzas that don't have a `:FOR[DMagic]` attached to them. Because MM
doens't yet play nicely with having both `:FOR` and `:AFTER` tags, simplying
adding a `:FOR` doens't guarantee everyone gets the behaviour they want; plus
we can't exactly have `:FOR[DMagic]:AFTER[DMagic]`.

Consequetly, I've adjusted `DMagicCommunityTechTree.cfg` to only apply its
changes if RP-0 is not loaded. If you prefer we could instead search for a
special token, rather than RP-0 specifically. For example:
`:NEEDS[!CTT_Config]`. RP-0 and other career mods can simply define
`CTT_Config` if they wish to use the CTT, but do their own part placement
inside it.

Thanks again for an awesome mod!

~ Paul