Apply special treatment of OUStringLiteral1 to MSVC 2015

Change-Id: I56e69fbdb555bb30cd88d75717d6f716c81ae237
Reviewed-on: https://gerrit.libreoffice.org/16804Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Thorsten Behrens <Thorsten.Behrens@CIB.de>

include/rtl/stringutils.hxx

@@ -77,7 +77,7 @@ template<char C> struct SAL_WARN_UNUSED OUStringLiteral1_ {
         "non-ASCII character in OUStringLiteral1");
     char const c = C;
 };
-#if defined _MSC_VER && _MSC_VER <= 1800 // Visual Studio 2013
+#if defined _MSC_VER && _MSC_VER <= 1900 // Visual Studio 2015
 template<char C> using OUStringLiteral1 = OUStringLiteral1_<C>;
 #pragma warning(disable: 4239)
 #else
@@ -216,8 +216,8 @@ template< int N >
 struct ExceptCharArrayDetector< const char[ N ] >
 {
 };
-#if defined LIBO_INTERNAL_ONLY && defined _MSC_VER && _MSC_VER <= 1800
-    // Visual Studio 2013
+#if defined LIBO_INTERNAL_ONLY && defined _MSC_VER && _MSC_VER <= 1900
+    // Visual Studio 2015
 template<char C> struct ExceptCharArrayDetector<OUStringLiteral1<C>> {};
 #endif