Update libGeoIP/GeoIPUpdate.c

My proxy wanted for '\r\n' for some of the constants at the top of the file.  

Also, I'm using a different approach for https://github.com/maxmind/geoip-api-c/commit/86a0335cca2293a4d2c45ad161b7c606b79990f6 commit that will keep the Proxy-Authorization line from being sent when the creds aren't present.