Remove unused exception parameter from instagram/wellbeing/sake/loggi…

…ng/SakeLoggingUtils.cpp

Summary:
`-Wunused-exception-parameter` has identified an unused exception parameter. This diff removes it.

This:
```
try {
    ...
} catch (exception& e) {
    // no use of e
}
```
should instead be written as
```
} catch (exception&) {
```

If the code compiles, this is safe to land.

Reviewed By: dmm-fb

Differential Revision: D58830900

fbshipit-source-id: cc1c55587e72af84941b5330d58f8cf92f937c6e

example_grpc/KatranGrpcService.cpp

@@ -188,7 +188,7 @@ Status KatranGrpcService::addRealForVip(
   try {
     Guard lock(giant_);
     res = lb_.addRealForVip(nr, vk);
-  } catch (const std::exception& e) {
+  } catch (const std::exception&) {
     res = false;
   }
   response->set_success(res);