Fixed missing include in minilog build

Change-Id: Ib4ff0595a6a496848922d9cb8462b2cd4cb83e99

internal/ceres/miniglog/glog/logging.h

diff --git a/internal/ceres/miniglog/glog/logging.h b/internal/ceres/miniglog/glog/logging.h
index 23bb614..28010ec 100644
--- a/internal/ceres/miniglog/glog/logging.h
+++ b/internal/ceres/miniglog/glog/logging.h
@@ -106,6 +106,7 @@
 #include <vector>
 
 #include "ceres/internal/disable_warnings.h"
+#include "ceres/internal/export.h"
 
 // Log severity level constants.
 // clang-format off