edje - signal callback matches/patterns try fix number 2

edje - signal callback matches/patterns try fix number 2

so i think there was also another bug as i saw this again now. this
should hopefully plug the signal/mtach memory bugs now by removing
and adding back to hash as the hash key relies on the memory addresses
of signal/src in the matches array which change on realloc. a bit
brute-forceey but... better than crashes.

@fix