manual: link to new common cs7-config.adoc, remove some dup of that

Related: OS#2767
Depends: Ia2508d4c7b0fef9cdc57e7e122799a480e340bf7 (osmo-gsm-manuals)
Change-Id: Ie88dd2c7f7318a31ae04fbd6930346d92141fde5
diff --git a/doc/manuals/osmomsc-usermanual.adoc b/doc/manuals/osmomsc-usermanual.adoc
index d680a51..848d9c0 100644
--- a/doc/manuals/osmomsc-usermanual.adoc
+++ b/doc/manuals/osmomsc-usermanual.adoc
@@ -22,6 +22,8 @@
 
 include::./common/chapters/logging.adoc[]
 
+include::./common/chapters/cs7-config.adoc[]
+
 include::{srcdir}/chapters/net.adoc[]
 
 include::./common/chapters/smpp.adoc[]