Update opamp-client/src/main/java/io/opentelemetry/opamp/client/internal/connectivity/http/OkHttpSender.java

Co-authored-by: Lauri Tulmin <[email protected]>

Author: LikeTheSalad

opamp-client/src/main/java/io/opentelemetry/opamp/client/internal/connectivity/http/OkHttpSender.java

@@ -78,7 +78,7 @@ private static class OkHttpResponse implements Response {
 
     private OkHttpResponse(okhttp3.Response response) {
       if (response.body() == null) {
-        throw new IllegalStateException();
+        throw new IllegalStateException("null response body not expected");
       }
       this.response = response;
     }