build: fix dev script

dev

@@ -360,7 +360,7 @@ EOF
 # copy cert files and acl.conf to etc
 copy_other_conf_files() {
     cp -r apps/emqx/etc/certs "$EMQX_ETC_DIR"/
-    cp -r apps/emqx/etc/base.hocon "$EMQX_ETC_DIR"/
+    cp -r apps/emqx_conf/etc/base.hocon "$EMQX_ETC_DIR"/
     cp apps/emqx_auth/etc/acl.conf "$EMQX_ETC_DIR"/
 }