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Co-authored-by: Lauri Tulmin <tulmin@gmail.com>

Author: trask

instrumentation/grpc-1.6/library/src/main/java/io/opentelemetry/instrumentation/grpc/v1_6/GrpcTelemetry.java

@@ -104,7 +104,7 @@ public void addClientInterceptor(ManagedChannelBuilder<?> builder) {
                     String target = (String) args[0];
                     return newTracingClientInterceptor(target);
                   }
-                  return null;
+                  return method.invoke(builder, args);
                 });
         interceptWithTargetMethod.invoke(null, builder, factory);
         return;