Drop ref to proper scoring in threshold description.

Author: MarkDaoust

site/en/tutorials/structured_data/imbalanced_data.ipynb

@@ -471,7 +471,7 @@
         "\n",
         "#### Other metrices\n",
         "\n",
-        "The following metrics take into account all possible choices of thresholds $t$, but they are not proper scoring rules and only assess the ranking of predictions, not their absolute values.\n",
+        "The following metrics take into account all possible choices of thresholds $t$.\n",
         "\n",
         "*   **AUC** refers to the Area Under the Curve of a Receiver Operating Characteristic curve (ROC-AUC). This metric is equal to the probability that a classifier will rank a random positive sample higher than a random negative sample.\n",
         "*   **AUPRC** refers to Area Under the Curve of the Precision-Recall Curve. This metric computes precision-recall pairs for different probability thresholds. \n",