Fixes occasional clicks and crackles

Some users heard intermittent clicks that got worse the longer WetDelay was
left running, and were most noticeable at small audio buffer sizes - the
settings you use when tracking with low latency. On rare occasions the plugin
could also overshoot and distort.

This release fixes that. The sound is otherwise unchanged: same delay times,
same character, same 80s grit.

Thanks to everyone who reported it.

Full Changelog: v1.1.4...v1.1.5