write_riemann_threshold: remove unused header

This fixes the build on EPEL7, which doesn't have ltdl-devel installed
(and it shouldn't have to since commit 98153711).

diff --git a/src/write_riemann_threshold.c b/src/write_riemann_threshold.c
index 992d856..8f6b4be 100644 (file)
--- a/src/write_riemann_threshold.c
+++ b/src/write_riemann_threshold.c
@@ -34,8 +34,6 @@
 #include "utils_threshold.h"
 #include "write_riemann_threshold.h"
 
-#include <ltdl.h>
-
 /*
  * Threshold management
  * ====================