Change issue number to point to tracking issue

Author: ChaiTRex

Diff for: src/liballoc/collections/btree/map.rs

@@ -2378,7 +2378,7 @@ impl<'a, K: Ord, V> Entry<'a, K, V> {
         }
     }
 
-    #[unstable(feature = "or_insert_with_key", issue = "70996")]
+    #[unstable(feature = "or_insert_with_key", issue = "71024")]
     /// Ensures a value is in the entry by inserting, if empty, the result of the default function,
     /// which takes the key as its argument, and returns a mutable reference to the value in the
     /// entry.

Diff for: src/libstd/collections/hash/map.rs

@@ -1943,7 +1943,7 @@ impl<'a, K, V> Entry<'a, K, V> {
         }
     }
 
-    #[unstable(feature = "or_insert_with_key", issue = "70996")]
+    #[unstable(feature = "or_insert_with_key", issue = "71024")]
     /// Ensures a value is in the entry by inserting, if empty, the result of the default function,
     /// which takes the key as its argument, and returns a mutable reference to the value in the
     /// entry.