targets/generic_ffberlin: remove some conflicting packages

* openvpn_openssl, openvpn_mbedtls have some files the would overwrite
  each other
* tcpdump, tcpdump-mini have some files the would overwrite each other
* luci-mod-freifunk-ui have some files that also are in
  luci-mod-freifunk

targets/generic_ffberlin

@@ -240,7 +240,6 @@ packages {
 'luci-lib-luaneightbl',
 'luci-lib-nixio',
 'luci-mod-admin-full',
-'luci-mod-freifunk-ui',
 'luci-proto-3g',
 'luci-proto-ipip',
 'luci-proto-ppp',
@@ -259,8 +258,6 @@ packages {
 'oonf-dlep-proxy',
 'oonf-dlep-radio',
 'oonf-olsrd2',
-'openvpn-mbedtls',
-'openvpn-openssl',
 'patch',
 'ppp',
 'ppp-mod-pppoe',
@@ -271,8 +268,6 @@ packages {
 'simple-tc',
 'snmp-utils',
 'tc',
-'tcpdump',
-'tcpdump-mini',
 'terminfo',
 'tmux',
 'uclibcxx',