rc.common: when reloading a service using procd, fall back to calling start instead of restart

This avoids unnecessary service restarts

Signed-off-by: Felix Fietkau <nbd@openwrt.org>

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@41490 3c298f89-4303-0410-b956-a3cf2f4a3e73