update numbering

Author: ben-schwen

NEWS.md

@@ -107,7 +107,7 @@ rowwiseDT(
 
 11. `tables()` now returns the correct size for data.tables over 2GiB, [#6607](https://github.com/Rdatatable/data.table/issues/6607). Thanks to @vlulla for the report and the PR.
 
-16. Joins on multiple columns, such as `x[y, on=c("x1==y1", "x2==y1")]`, could fail during type coercions if `x1` and `x2` had different but still compatible types, [#6602](https://github.com/Rdatatable/data.table/issues/6602). This was particularly unexpected when all columns `x1, x2, and y1` were of the same class e.g. `Date` but differed in their underlying types. Thanks to Benjamin Schwendinger for the report and the fix.
+12. Joins on multiple columns, such as `x[y, on=c("x1==y1", "x2==y1")]`, could fail during type coercions if `x1` and `x2` had different but still compatible types, [#6602](https://github.com/Rdatatable/data.table/issues/6602). This was particularly unexpected when all columns `x1, x2, and y1` were of the same class e.g. `Date` but differed in their underlying types. Thanks to Benjamin Schwendinger for the report and the fix.
 
 ## NOTES