unicode.cpp: make it compile again

the removal of this header in [ea1d9cb3/lyxgit] was too much

diff --git a/src/support/unicode.cpp b/src/support/unicode.cpp
index 574d9f904f4e620f9459ec96201cb9b99d693d3e..8b0f9cb0db416b80a65206326b1b215d9ad4e4c8 100644 (file)
--- a/src/support/unicode.cpp
+++ b/src/support/unicode.cpp
@@ -23,6 +23,7 @@
 #include <cerrno>
 #include <map>
 #include <ostream>
+#include <string>
 
 
 using namespace std;