message: Fix new Log unit test
  the test was flaky because I specified the format string for the process id
  incorrectly. This should fix it.
diff: @@ -48,7 +48,7 @@ TEST(LogTest, log_options) {
  "World 47\n",
  GetLogString(LLDB_LOG_OPTION_PREPEND_FILE_FUNCTION, "Hello World {0}", 47));
  - EXPECT_EQ(llvm::formatv("[{0}/{1}] Hello World 47\n",
  + EXPECT_EQ(llvm::formatv("[{0,0+4}/{1,0+4}] Hello World 47\n",
  Host::GetCurrentProcessID(),
  Host::GetCurrentThreadID())
  .str(),
  