Terminate sed substitution command with semicolon to fix error on OSX.

  sed: 1: "/#define *SWITCH_VERSIO ...": bad flag in substitute command: '}'

Reported-by: scruz in #freeswitch @ irc.freenode.net
Signed-off-by: Stefan Knoblich <s.knoblich@axsentis.de>

Makefile.am

@@ -422,7 +422,7 @@ src/include/switch_version.h: src/include/switch_version.h.in Makefile build/pri
 	@cat $< > $@; \
 	if [ -d .git ] && [ -n "$$(which git)" ]; then \
 	  xver="$$(./build/print_git_revision)"; \
-	  sed -e "/#define *SWITCH_VERSION_REVISION/{s/\"\([^\"]*\)\"/\"\1$$xver\"/}" \
+	  sed -e "/#define *SWITCH_VERSION_REVISION/{s/\"\([^\"]*\)\"/\"\1$$xver\"/;}" \
 	    $< > $@; \
 	fi;