package/{collectd, domoticz}: fix outdated dependencies for mosquitto

package/{collectd, domoticz}: fix outdated dependencies for mosquitto

In 4fc62e1eb6b3adbfc3d3eb7f841275ae8cd1b424, we removed arch/toolchain
dependencies from the mosquitto library (MMU, !STATIC, SYNC4), and moved
them to the mosquitto broker only.

All the packages modified here only need the mosquitto library, so they
shouldn't have those depends anymore; but this was never done before.

Signed-off-by: Titouan Christophe <titouan.christophe@railnova.eu>
[Peter: leave mmu/!static dependency for domoticz as it uses fork()/looks
	for libmosquitto.so]
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>