Prevent instantiation of ErrorMessage class by making the constructor private

Author: angelmp01

api-project/src/main/java/org/opendevstack/apiservice/project/exception/ErrorMessage.java

@@ -5,6 +5,8 @@ public class ErrorMessage {
     public static final String NOT_FOUND = "Not Found";
     public static final String FORBIDDEN = "Forbidden";
     public static final String BAD_REQUEST = "Bad Request";
-
-    public ErrorMessage() {}
+    
+    private ErrorMessage() {
+        // prevent instantiation
+    }
 }