Move import line

Author: Joel Allred

src/solvers/strings/string_refinement.cpp

@@ -18,7 +18,6 @@ Author: Alberto Griggio, [email protected]
 ///   Ghosh.
 
 #include "string_refinement.h"
-#include "string_constraint_instantiation.h"
 
 #include <iomanip>
 #include <numeric>
@@ -30,6 +29,8 @@ Author: Alberto Griggio, [email protected]
 #include <util/magic.h>
 #include <util/simplify_expr.h>
 
+#include "string_constraint_instantiation.h"
+
 static bool is_valid_string_constraint(
   messaget::mstreamt &stream,
   const namespacet &ns,