message: Make Table::get_search_index not throw
  If search index is not present, just return nullptr.
diff: @@ -459,12 +459,10 @@ public:
  double average_float(size_t column_ndx, size_t* value_count = nullptr) const;
  double average_double(size_t column_ndx, size_t* value_count = nullptr) const;
  - // Searching
  + // Will return pointer to search index accessor. Will return nullptr if no index
  StringIndex* get_search_index(size_t column_ndx) const noexcept
  {
  - if (!has_search_index(column_ndx)) {
  - throw(std::runtime_error(""));
  - }
  + REALM_ASSERT(column_ndx < m_index_accessors.size());
  return m_index_accessors[column_ndx];
  }
  