RIPD-108:  Use a self-signed certificate for peers

If you want, you can include __FILE__ and __LINE__ when constructing your message to std::runtime_error.  However also consider the /Applications/Utilities/Console.app utility.  Double click it and search the list of "User Diagnostic Reports".  They are listed by application name and date.  When rippled is compiled with -g the provided information is fairly impressive.  Other platforms have similar facilities, though I currently think OSX's is best.