Fixes rrror message in X.dot(w) (#2688)

Co-authored-by: KexinFeng <[email protected]>
Co-authored-by: Frank Liu <[email protected]>

engines/pytorch/pytorch-engine/src/main/java/ai/djl/pytorch/engine/PtNDArray.java

@@ -1351,8 +1351,9 @@ public PtNDArray dot(NDArray other) {
         int otherDim = other.getShape().dimension();
         if (selfDim != otherDim || selfDim > 2) {
             throw new UnsupportedOperationException(
-                    "Dimension mismatch or high dimensional dot operation is not supported. Please"
-                            + " use .matMul instead.");
+                    "Dimension mismatch or dimension is greater than 2.  Dot product is only"
+                            + " applied on two 1D vectors. For high dimensions, please use .matMul"
+                            + " instead.");
         }
         return JniUtils.dot(this, manager.from(other));
     }