fixup fromstring return types (#10162)

in https://github.com/certbot/certbot/pull/9124 we had the problem of
certbot-nginx's `Addr.fromstring` method possibly returning None which
is not possible in the `Addr` method in the certbot base class or in
certbot-apache. we fixed this by telling mypy the common
`Addr.fromstring` method returns an `Optional[Addr]` (despite it
actually always returning an `Addr`) and then unnecessarily complicating
certbot-apache's code a bit. the need for extra complexity with this
approach is going even further in
https://github.com/certbot/certbot/pull/10151 where we have to use
`cast` to assure mypy that the type isn't actually `Optional`. i
personally don't like all this

certbot-apache/certbot_apache/_internal/configurator.py

@@ -994,9 +994,7 @@ class ApacheConfigurator(common.Configurator):
         for arg in args:
             arg_value = self.parser.get_arg(arg)
             if arg_value is not None:
-                addr = obj.Addr.fromstring(arg_value)
-                if addr is not None:
-                    addrs.add(addr)
+                addrs.add(obj.Addr.fromstring(arg_value))
         is_ssl = False
 
         if self.parser.find_dir("SSLEngine", "on", start=path, exclude=False):
@@ -1126,9 +1124,7 @@ class ApacheConfigurator(common.Configurator):
         """
         addrs = set()
         for param in node.parameters:
-            addr = obj.Addr.fromstring(param)
-            if addr:
-                addrs.add(addr)
+            addrs.add(obj.Addr.fromstring(param))
 
         is_ssl = False
         # Exclusion to match the behavior in get_virtual_hosts_v2
@@ -1646,10 +1642,9 @@ class ApacheConfigurator(common.Configurator):
         for addr in ssl_addr_p:
             old_addr = obj.Addr.fromstring(
                 str(self.parser.get_arg(addr)))
-            if old_addr:
-                ssl_addr = old_addr.get_addr_obj("443")
-                self.parser.aug.set(addr, str(ssl_addr))
-                ssl_addrs.add(ssl_addr)
+            ssl_addr = old_addr.get_addr_obj("443")
+            self.parser.aug.set(addr, str(ssl_addr))
+            ssl_addrs.add(ssl_addr)
 
         return ssl_addrs