package/nginx: replace NGINX_CPE_ID_VENDOR

nginx has been replaced by f5 since February 2022:

<cpe-item name="cpe:/a:nginx:nginx:1.18.0" deprecated="true" deprecation_date="2022-02-22T19:26:32.967Z">
      <reference href="https://nginx.org/en/CHANGES-1.18">Change Log</reference>
    <cpe-23:cpe23-item name="cpe:2.3:a:nginx:nginx:1.18.0:*:*:*:*:*:*:*">
        <cpe-23:deprecated-by name="cpe:2.3:a:f5:nginx:1.18.0:*:*:*:*:*:*:*" type="NAME_CORRECTION"/>

https://nvd.nist.gov/products/cpe/search/results?namingFormat=2.3&keyword=cpe%3A2.3%3Aa%3Af5%3Anginx

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/nginx/nginx.mk

@@ -8,7 +8,7 @@ NGINX_VERSION = 1.20.1
 NGINX_SITE = http://nginx.org/download
 NGINX_LICENSE = BSD-2-Clause
 NGINX_LICENSE_FILES = LICENSE
-NGINX_CPE_ID_VENDOR = nginx
+NGINX_CPE_ID_VENDOR = f5
 NGINX_DEPENDENCIES = \
 	host-pkgconf \
 	$(if $(BR2_PACKAGE_LIBXCRYPT),libxcrypt)