Fix incorrect method name

Author: pierredup

components/locale.rst

@@ -66,7 +66,7 @@ When using the ClassLoader component following code is sufficient to supplement
     $localeCodes = Locale::getLocales();
 
     // Get ICU versions
-    $icuVersion = Locale::getIcuVersion();
+    $icuVersion = Locale::getIntlIcuVersion();
     $icuDataVersion = Locale::getIcuDataVersion();
 
 .. _Packagist: https://packagist.org/packages/symfony/locale