Makefile: add ext_conf_template.txt to extension build rule.

Makefile

@@ -11,7 +11,7 @@ RELEASE_DATE = $(shell date '+%Y%m%d%H%M')
 GIT_REVISION_SHORT = $(shell git rev-parse --short HEAD || true)
 GIT_REVISION_LONG = $(shell git rev-parse HEAD || true)
 
-EXTENSION_CONTENT = Classes Configuration Documentation qfq Resources ext_emconf.php ext_localconf.php ext_tables.php ext_icon.png config.qfq.example.ini RELEASE.txt
+EXTENSION_CONTENT = Classes Configuration Documentation qfq Resources ext_emconf.php ext_localconf.php ext_tables.php ext_icon.png ext_conf_template.txt config.qfq.example.ini RELEASE.txt
 
 DISTDIR=dist