event_graph: minor fix to log output

src/event_graph/mod.rs

@@ -408,7 +408,7 @@ impl EventGraph {
                         {
                             debug!(
                                 target: "event_graph::dag_sync()",
-                                "Found upper missing parent event{}", upper_parent,
+                                "Found upper missing parent event {}", upper_parent,
                             );
                             missing_parents.insert(*upper_parent);
                         }

src/event_graph/proto.rs

@@ -390,7 +390,7 @@ impl ProtocolEventGraph {
                             {
                                 debug!(
                                     target: "event_graph::protocol::handle_event_put()",
-                                    "Found upper missing parent event{}", upper_parent,
+                                    "Found upper missing parent event {}", upper_parent,
                                 );
                                 missing_parents.insert(*upper_parent);
                             }