bpo-30911: Fix a crash in json on platforms with unsigned char (#2684)

segevfiner · serhiy-storchaka · commit 541bd28941af · 2017-07-13T08:52:08.000+03:00
when pass bad strict argument.
diff --git a/Modules/_json.c b/Modules/_json.c
@@ -18,7 +18,7 @@ static PyTypeObject PyEncoderType;
 
 typedef struct _PyScannerObject {
     PyObject_HEAD
-    char strict;
+    signed char strict;
     PyObject *object_hook;
     PyObject *object_pairs_hook;
     PyObject *parse_float;
