clang warnings because of "empty" hs_service.c file in 0.3.0
Currently (in 0.3.0) the code in hs_service.c
is disabled using #ifdef TOR_UNIT_TESTS
and is only used for unittests. We will remove these #ifdef
guards in 0.3.2 when we merge the rest of the service-side code.
Unfortunately, as it seems having an empty .c file is no good, since empty translation units (i.e. files) are undefined behavior in C.
Sebastian pointed this out, and said that his clang is throwing warnings at him because of that. He says that compilation proceeds normally, but it might be a good thing to fix anyhow.
We could fix this by adding a static variable on top to silence the warning, or by removing the #ifdef guards.