message: Update sig_node_test.cc
diff: @@ -986,7 +986,7 @@ TEST_F(SignatureTest, ComputeOneRoundLinear) {
  EXPECT_THAT(hash_size, ElementsAre(4, 5, 5, 6, 6));
  }
  -// On a linear topology where the cental node has been already marked as unique
  +// On a linear topology where the central node has been already marked as unique
  // (yeah, not a very realistic case but tests the situations when the
  // disconnected subgraphs get created).
  TEST_F(SignatureTest, ComputeOneRoundSplitLinear) {
  