Apply client initial padding consistently

Fixes unconditional padding of close packets

quinn-proto/src/connection/mod.rs

@@ -612,8 +612,6 @@ where
                         "tried to make a close packet when the connection wasn't closed"
                     ),
                 }
-                // A close frame in the initial space requires padding
-                pad_datagram = true;
                 coalesce = false;
                 // We don't want to send 2 close packets
                 close = false;
@@ -634,6 +632,8 @@ where
                 pad_datagram |= sent.requires_padding;
             }
 
+            pad_datagram |= space_id == SpaceId::Initial && self.side.is_client();
+
             // Don't increment space_idx.
             // We stay in the current space and check if there is more data to send.
         }
@@ -2923,10 +2923,6 @@ where
         let space = &mut self.spaces[space_id];
         let is_0rtt = space_id == SpaceId::Data && space.crypto.is_none();
 
-        if space_id == SpaceId::Initial && self.side.is_client() {
-            sent.requires_padding = true;
-        }
-
         // HANDSHAKE_DONE
         if !is_0rtt && mem::replace(&mut space.pending.handshake_done, false) {
             buf.write(frame::Type::HANDSHAKE_DONE);