Set .cookie file path.

[sslisen]

I installed Bitcoin Core on E: drive instead of the default C: drive. So the conf and .cookie files are located in the Bitcoin directory on E: drive. When I deployed Pipe-Wallet following the instructions, it could not find the cookie and conf files. I had to manually copy the two files from E: drive to the corresponding directory on C: drive. However, there is a problem: the two files are on E: drive and will be automatically updated with the Bitcoin Core. However, the two files that I manually copied to C: drive will not be automatically updated. I may need to regularly copy the two files to C: drive. I hope that a custom option for the cookie and conf paths can be added to the default.config file, so that we can set the right path of these two files.