Update ICU to 58.1

source/common/wintz.c

Index: source/common/wintz.c
diff --git a/source/common/wintz.c b/source/common/wintz.c
index fa04588e38fae1809f5aa82b3bdc01e79c60b0b2..a8696af39d4af0201eebe87c80a212f357a6a996 100644
--- a/source/common/wintz.c
+++ b/source/common/wintz.c
@@ -1,3 +1,5 @@
+// Copyright (C) 2016 and later: Unicode, Inc. and others.
+// License & terms of use: http://www.unicode.org/copyright.html
 /*
 ********************************************************************************
 *   Copyright (C) 2005-2015, International Business Machines
@@ -352,6 +354,7 @@ uprv_detectWindowsTimeZone() {
                     tryPreVistaFallback = FALSE;
                 }
             }
+            ures_close(winTZ);
         }
     }