fix warning for members order

include/aidge/data/DataProvider.hpp

@@ -35,6 +35,9 @@ private:
     // Desired size of the produced batches
     const std::size_t mBatchSize;
 
+    // The backend for data tensors
+    std::string mBackend;
+
     // Enable random shuffling for learning
     const bool mShuffle;
 
@@ -56,8 +59,6 @@ private:
     // Size of the Last batch
     std::size_t mLastBatchSize;
 
-    std::string mBackend;
-
     // Store each modality dimensions, backend and type
     std::vector<std::vector<std::size_t>> mDataDims;
     std::vector<std::string> mDataBackends;