Call the right method to get string from JSON tree

src/main/java/org/genesys2/server/service/impl/EasySMTAConnector.java

@@ -100,7 +100,7 @@ public class EasySMTAConnector implements EasySMTA {
 					// TODO Report various errorCodes!
 
 				} else {
-					return objectMapper.readValue(tree.asText(), EasySMTA.EasySMTAUserData.class);
+					return objectMapper.readValue(tree.toString(), EasySMTA.EasySMTAUserData.class);
 				}
 			}
 		} catch (final ClientProtocolException e) {