Panic when MulticastInterfaces/Regex has errors.

[shibe2]

Current behavior

yggdrasil-go/cmd/yggdrasil/main.go

Line 242 in 49c424e

 Regex:    regexp.MustCompile(intf.Regex), 

MustCompile is like Compile but panics if the expression cannot be parsed.

Expected behavior

Print a message that points to MulticastInterfaces and includes error from regexp.Compile. Then either exit or ignore the erroneous entry.

[Slex]

This looks like expected behavior: almost all config errors cause panic

[shibe2]

almost all config errors cause panic

Gross.