Fix spurious "Failed to set parent context on span" error

This would happen when the `info` log level is surpressed, and therefore
the request span would not be enabled and fail to set the parent OTEL
context.

Author: sandhose

crates/cli/src/server.rs

@@ -143,11 +143,13 @@ fn make_http_span<B>(req: &Request<B>) -> Span {
         propagator.extract_with_context(&context, &extractor)
     });
 
-    if let Err(err) = span.set_parent(parent_context) {
-        tracing::error!(
-            error = &err as &dyn std::error::Error,
-            "Failed to set parent context on span"
-        );
+    if !span.is_disabled() {
+        if let Err(err) = span.set_parent(parent_context) {
+            tracing::error!(
+                error = &err as &dyn std::error::Error,
+                "Failed to set parent context on span"
+            );
+        }
     }
 
     span