_tkinter: Fix refleak in getint() (#2153)

PyNumber_Int() creates a new reference: need to decrement result
reference counter.
diff --git a/Modules/_tkinter.c b/Modules/_tkinter.c
index 46cc64d..6053e4b 100644
--- a/Modules/_tkinter.c
+++ b/Modules/_tkinter.c
@@ -2131,8 +2131,12 @@
     result = fromWideIntObj(self, value);
 #endif
     Tcl_DecrRefCount(value);
-    if (result != NULL)
-        return PyNumber_Int(result);
+    if (result != NULL) {
+        PyObject *resint = PyNumber_Int(result);
+        Py_DECREF(result);
+        return resint;
+    }
+
     if (PyErr_Occurred())
         return NULL;
 #else