fix HTTP user agent constant

include/villas/config.h.in

@@ -42,7 +42,8 @@
 
 #define PROJECT_HOMEPAGE_URL	"@CMAKE_PROJECT_HOMEPAGE_URL@"
 #define PROJECT_NAME		"@CMAKE_PROJECT_DESCRIPTION@"
-#define USER_AGENT		"@CMAKE_PROJECT_DESCRIPTION@ (@CMAKE_PROJECT_BUILD_ID@)"
+
+#define HTTP_USER_AGENT		PROJECT_NAME " (" PROJECT_BUILD_ID ")"
 
 /* Paths */
 #define PREFIX			"@CMAKE_INSTALL_PREFIX@"