REORG: include: move fcgi-app.h to haproxy/fcgi-app{,-t}.h

Only arg-t.h was missing from the types to get arg_list.
diff --git a/src/fcgi-app.c b/src/fcgi-app.c
index 9097dab..629c677 100644
--- a/src/fcgi-app.c
+++ b/src/fcgi-app.c
@@ -15,6 +15,7 @@
 #include <haproxy/chunk.h>
 #include <common/cfgparse.h>
 #include <haproxy/errors.h>
+#include <haproxy/fcgi-app.h>
 #include <haproxy/filters.h>
 #include <haproxy/http_fetch.h>
 #include <haproxy/http_htx.h>
@@ -25,7 +26,6 @@
 
 #include <haproxy/global.h>
 
-#include <proto/fcgi-app.h>
 #include <proto/log.h>
 #include <proto/proxy.h>
 #include <proto/server.h>