pkg/kamailio/deb: add virtual-mysql-client as an alternative of mysql-client at kamailio-mysql-modules package

missing files

fixes #376

pkg/kamailio/deb/sid/control

@@ -238,7 +238,7 @@ Architecture: linux-any
 Multi-Arch: same
 Pre-Depends: ${misc:Pre-Depends}
 Depends: kamailio (= ${binary:Version}),
-         mysql-client,
+         mysql-client | virtual-mysql-client,
          ${misc:Depends},
          ${shlibs:Depends}
 Description: MySQL database connectivity module for Kamailio

pkg/kamailio/deb/stretch/control

@@ -238,7 +238,7 @@ Architecture: linux-any
 Multi-Arch: same
 Pre-Depends: ${misc:Pre-Depends}
 Depends: kamailio (= ${binary:Version}),
-         mysql-client,
+         mysql-client | virtual-mysql-client,
          ${misc:Depends},
          ${shlibs:Depends}
 Description: MySQL database connectivity module for Kamailio