Trap HTTPS cert errors when accessing arbitrary Token URIs and display more sensible and less scary message

Security alert reported in console. Should someone be alerted to this?
```
2022-03-15 07:18:50.926269+0800 AlphaWallet[8553:56995] Task <653B769A-5117-4036-AEE6-3DC8331080ED>.<190> finished with error [-1202] Error Domain=NSURLErrorDomain Code=-1202 "The certificate for this server is invalid. You might be connecting to a server that is pretending to be “mcp.town” which could put your confidential information at risk." UserInfo={NSLocalizedRecoverySuggestion=Would you like to connect to the server anyway?, _kCFStreamErrorDomainKey=3, NSErrorPeerCertificateChainKey=(
"",
"",
"",
""
), NSErrorClientCertificateStateKey=0, NSErrorFailingURLKey=https://mcp.town/api/wp/3001, NSErrorFailingURLStringKey=https://mcp.town/api/wp/3001, NSUnderlyingError=0x14a59bba0 {Error Domain=kCFErrorDomainCFNetwork Code=-1202 "(null)" UserInfo={_kCFStreamPropertySSLClientCertificateState=0, kCFStreamPropertySSLPeerTrust=, _kCFNetworkCFStreamSSLErrorOriginalValue=-9843, _kCFStreamErrorDomainKey=3, _kCFStreamErrorCodeKey=-9843, kCFStreamPropertySSLPeerCertificates=(
"",
"",
"",
""
)}}, _NSURLErrorRelatedURLSessionTaskErrorKey=(
"LocalDataTask <653B769A-5117-4036-AEE6-3DC8331080ED>.<190>"
), _kCFStreamErrorCodeKey=-9843, _NSURLErrorFailingURLSessionTaskErrorKey=LocalDataTask <653B769A-5117-4036-AEE6-3DC8331080ED>.<190>, NSURLErrorFailingURLPeerTrustErrorKey=, NSLocalizedDescription=The certificate for this server is invalid. You might be connecting to a server that is pretending to be “mcp.town” which could put your confidential information at risk.}
```