software/beremiz-ide: set OPENSSL_ROOT_DIR to slapos' openssl

otherwise it probably uses system's openssl.

Setting rpath seems not needed because we are using
-DBUILD_SHARED_LIBS=OFF here.

software/beremiz-ide/software.cfg

@@ -55,6 +55,7 @@ configure-options =
   -DUA_ENABLE_SUBSCRIPTIONS=ON
   -DUA_NAMESPACE_ZERO=REDUCED
   -DUA_ENABLE_ENCRYPTION=OPENSSL
+  -DOPENSSL_ROOT_DIR=${openssl:location}
 shared = false
 post-install =
   mkdir -p @@LOCATION@@/build/bin