Raise exception on proxy in .ovpn

Passepartout/Sources/VPN/TunnelKitProvider+FileConfiguration.swift

@@ -51,6 +51,8 @@ extension TunnelKitProvider.Configuration {
 
         static let fragment = Utils.regex("^fragment +\\d+")
 
+        static let proxy = Utils.regex("^\\w+-proxy")
+        
         static let keyDirection = Utils.regex("^key-direction +\\d")
         
         static let externalFiles = Utils.regex("^(ca|cert|key|tls-auth|tls-crypt)")
@@ -211,6 +213,9 @@ extension TunnelKitProvider.Configuration {
             Regex.fragment.enumerateArguments(in: line) { (_) in
                 unsupportedError = ApplicationError.unsupportedConfiguration(option: "fragment")
             }
+            Regex.proxy.enumerateArguments(in: line) { (_) in
+                unsupportedError = ApplicationError.unsupportedConfiguration(option: "proxy: \"\(line)\"")
+            }
             Regex.externalFiles.enumerateArguments(in: line) { (_) in
                 unsupportedError = ApplicationError.unsupportedConfiguration(option: "external file: \"\(line)\"")
             }

README.md

@@ -76,6 +76,7 @@ Unsupported (probably ever):
 - Compression
 	- `--comp-lzo` other than `no`
 	- `--compress` other than empty
+- Proxy
 - External file references (inline `<block>` only)
 
 Ignored: