server: Peers method now grabs data directly with read mutex
server: Peers method now grabs data directly with read mutex

This commit modifies the Peers method on the server such that a caller
is able to query this method without the main serger goroutines
started. This is a small component in a larger change which will let us
start the RPC server independently of the server.

LightningNetwork/lnd,ddustin/lnd,aakselrod/lnd,aakselrod/lnd,ddustin/lnd,AndrewSamokhvalov/lnd,AndrewSamokhvalov/lnd,LightningNetwork/lnd