Make client report connection issues to servers

src/main/java/com/sheepit/client/Client.java

@@ -1090,12 +1090,16 @@ import okhttp3.HttpUrl;
 					// the client cannot recover from this error (it's server side config) so exit the retry loop
 					confirmJobReturnCode = Type.IMAGE_TOO_LARGE;
 					break retryLoop;
+					
+				case SERVER_CONNECTION_FAILED:
+					confirmJobReturnCode = Type.NETWORK_ISSUE;
+					break;
 				
 				case ERROR_BAD_RESPONSE:
 					// set the error and retry on next loop
 					confirmJobReturnCode = Type.ERROR_BAD_UPLOAD_RESPONSE;
 					break;
-				
+					
 				default:
 					// do nothing, try to do a request on the next loop
 					break;

src/main/java/com/sheepit/client/Error.java

@@ -108,6 +108,7 @@ public class Error {
 		ERROR_NO_ROOT(2),
 		ERROR_BAD_RESPONSE(3),
 		ERROR_REQUEST_FAILED(5),
+		SERVER_CONNECTION_FAILED(6),
 		;
 		
 		private final int id;

src/main/java/com/sheepit/client/Server.java

@@ -650,6 +650,13 @@ public class Server extends Thread {
 			
 			return ServerCode.UNKNOWN;
 		}
+		catch (ConnectException e) {
+			StringWriter sw = new StringWriter();
+			PrintWriter pw = new PrintWriter(sw);
+			e.printStackTrace(pw);
+			this.log.error(checkpoint, String.format("Server::HTTPSendFile Error in upload process. Exception %s stacktrace ", e.getMessage()) + sw.toString());
+			return ServerCode.SERVER_CONNECTION_FAILED;
+		}
 		catch (IOException e) {
 			StringWriter sw = new StringWriter();
 			PrintWriter pw = new PrintWriter(sw);