docs: add iconv-lite 0.7.0 changes to history entry (#645)

Author: Phillip9587

HISTORY.md

@@ -5,6 +5,8 @@ unreleased
 * deps: 
   * type-is@^2.0.1
   * iconv-lite@^0.7.0
+    * Handle split surrogate pairs when encoding UTF-8
+    * Avoid false positives in `encodingExists` by using prototype-less objects 
   * raw-body@^3.0.1
   * debug@^4.4.3