Add header "Content-type".

Author: BeauneNuits

src/main/java/fr/rabian/ovhApi/core/beans/AppManager.java

@@ -162,6 +162,7 @@ private String sendReq(String path, String method, Consumer c, String body) thro
         headers.add(new Header("X-Ovh-Application", app.getPubKey()));
         headers.add(new Header("X-Ovh-Consumer", c.getConsumerKey()));
         headers.add(new Header("Accept", "application/json"));
+        headers.add(new Header("Content-Type", "application/json;charset=utf-8"));
         headers.add(new Header("X-Ovh-Timestamp", Long.toString(time)));
         headers.add(new Header("X-Ovh-Signature", sig));