Remove const from class variables

It prohibits copy construction, copy assignment and move semantics.

src/base/http/httperror.h

@@ -39,8 +39,8 @@ public:
     QString statusText() const;
 
 private:
-    const int m_statusCode;
+    int m_statusCode;
-    const QString m_statusText;
+    QString m_statusText;
 };
 
 class BadRequestHTTPError : public HTTPError

src/base/indexrange.h

@@ -57,8 +57,8 @@ public:
     }
 
 private:
-    const IndexType m_first;
+    IndexType m_first;
-    const IndexType m_last;
+    IndexType m_last;
 };
 
 template <typename T>

src/webui/api/apierror.h

@@ -47,5 +47,5 @@ public:
     APIErrorType type() const;
 
 private:
-    const APIErrorType m_type;
+    APIErrorType m_type;
 };