tls: renamed sip-router_cert.sh to tls_cert.sh

- it is specific to the module, not the flavour of the application

src/modules/tls/Makefile

@@ -38,7 +38,7 @@ include ../../Makefile.modules
 
 
 install-tls-cert: $(cfg_prefix)/$(cfg_dir)
-	MAIN_NAME=$(MAIN_NAME) ./$(SCR_NAME)_cert.sh -d $(cfg_prefix)/$(cfg_dir)
+	MAIN_NAME=$(MAIN_NAME) ./tls_cert.sh -d $(cfg_prefix)/$(cfg_dir)
 
 install-cfg:
 	@if ! [ -d $(cfg_prefix)/$(cfg_dir) ]; then \