[headers] Remove warnings from Eigen.

include/dynamic-graph/eigen-io.h

@@ -9,8 +9,10 @@
 
 #include <boost/format.hpp>
 #include <boost/numeric/conversion/cast.hpp>
-
+#pragma GCC diagnostic push
+#pragma GCC system_header
 #include <Eigen/Geometry>
+#pragma GCC diagnostic pop
 #include <dynamic-graph/exception-signal.h>
 #include <dynamic-graph/linear-algebra.h>