Fix issue where Share Avatar Collections imported from FTN were saved as files

in data/fido with the node number encoded twice (once in hex and once in
decimal):
006702c1.705.VERT.misc.bin

This is a harmless bug, but an unintentional one. It would also result in
unexpected filenames in text/avatars:
705.VERT.misc.bin

So... this commit should remove the "705." from these filenames.