kamailio-kemi-framework: removed link to acc module docs in section header

- it is added automatically for every module

kamailio-kemi-framework/docs/modules/acc/acc.header.md

@@ -1,5 +1 @@
 The functions exported by `acc` module to KEMI are listed in the next sections.
-
-The documentation of `acc` module is available online at:
-
-  * [acc.html](https://kamailio.org/docs/modules/devel/modules/acc.html)