Fix exec:SetIntVector [CORRECTIVE]

Fix copied from webuade: https://bitbucket.org/wothke/uade-2.13/src/7ed9664ee60b00cedca4f575696d516082509c1a/amigasrc/score/score.s#lines-5009

Affects some AProSys, DigitalSonixChrome, FaceTheMusic, Musicline, TFMX and few Custom mods: https://github.com/mvtiaine/audacious-uade/commit/9beaa47e9fef7f11e0203f3aa6d81f4e4e37fa13

Again just small inaudible changes in audio output due to init timing difference.

Cherry picked 9c4acaee from !38 also to this branch for exec/interrupts.i to avoid conflict.

Fixes #65