Add gsm-devel as a package to install on redhat based systems.

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@303547 65c4cc65-6c06-0410-ace0-fbb531ad65f3

contrib/scripts/install_prereq

@@ -32,7 +32,7 @@ PACKAGES_DEBIAN="$PACKAGES_DEBIAN libresample-dev libc-client-dev binutils-dev"
 PACKAGES_RH="automake gcc gcc-c++ ncurses-devel openssl-devel libxml2-devel unixODBC-devel libcurl-devel libogg-devel libvorbis-devel speex-devel"
 PACKAGES_RH="$PACKAGES_RH spandsp-devel freetds-devel net-snmp-devel iksemel-devel openais-devel newt-devel popt-devel libtool-ltdl-devel lua-devel"
 PACKAGES_RH="$PACKAGES_RH libsqlite3x-devel radiusclient-ng-devel portaudio-devel postgresql-devel libresample-devel neon-devel libical-devel"
-PACKAGES_RH="$PACKAGES_RH openldap-devel gmime22-devel sqlite2-devel mysql-devel bluez-libs-devel jack-audio-connection-kit-devel"
+PACKAGES_RH="$PACKAGES_RH openldap-devel gmime22-devel sqlite2-devel mysql-devel bluez-libs-devel jack-audio-connection-kit-devel gsm-devel"
 
 PACKAGES_OBSD="popt gmake wget libxml libogg libvorbis curl iksemel spandsp speex iodbc freetds-0.63p1-msdblib mysql-client gmime sqlite sqlite3 jack"