Remove unneeded noexcept specifier on FakeClock::now().

In C++17 mode, clang complains if the noexcept specification on the
declaration and the definition do not match. Since noexcept is typically
only used in conjunction with move constructors to provide strong
exception safety, just remove its usage here instead.

Bug: 752720
Change-Id: Ia0d5466f05ad65073d358ab25442c779efaa5a5f
Reviewed-on: https://chromium-review.googlesource.com/c/openscreen/+/3283982
Commit-Queue: Jordan Bayles <jophba@chromium.org>
Reviewed-by: Jordan Bayles <jophba@chromium.org>
diff --git a/platform/test/fake_clock.cc b/platform/test/fake_clock.cc
index ae43d9a..c40ba63 100644
--- a/platform/test/fake_clock.cc
+++ b/platform/test/fake_clock.cc
@@ -30,7 +30,7 @@
   now_.store(kInvalid, std::memory_order_release);
 }
 
-Clock::time_point FakeClock::now() noexcept {
+Clock::time_point FakeClock::now() {
   const Clock::time_point value = now_.load(std::memory_order_acquire);
   OSP_CHECK_NE(value, kInvalid) << "No FakeClock instance!";
   return value;