fix(ios): remove new line character in multipart/form-data requests

Removes new line characters `\r\n` which are incorrectly appended to the
data of multipart/form-data requests. This change removes these new line
characters in order to comply with the specifications, as defined here:
https://www.w3.org/TR/html401/interact/forms.html#h-17.13.4.2

Fixes: ionic-team#6748

ios/Capacitor/Capacitor/Plugins/CapacitorUrlRequest.swift

@@ -127,14 +127,12 @@ open class CapacitorUrlRequest: NSObject, URLSessionTaskDelegate {
                 data.append("\r\n".data(using: .utf8)!)
 
                 data.append(Data(base64Encoded: value)!)
-
-                data.append("\r\n".data(using: .utf8)!)
             } else if type == "string" {
                 data.append("\r\n--\(boundary)\r\n".data(using: .utf8)!)
                 data.append("Content-Disposition: form-data; name=\"\(key!)\"\r\n".data(using: .utf8)!)
                 data.append("\r\n".data(using: .utf8)!)
+
                 data.append(value.data(using: .utf8)!)
-                data.append("\r\n".data(using: .utf8)!)
             }
 
         }