Get rid of push_back in favor of emplace_back

Change-Id: I4a0096441ed725eb21e42eb9cc17a173929e3788
diff --git a/src/grammars.hpp b/src/grammars.hpp
index 478e49f..742115b 100644
--- a/src/grammars.hpp
+++ b/src/grammars.hpp
@@ -211,7 +211,7 @@
             parserContext.m_tmpListPath = parserContext.currentDataPath();
             parserContext.m_tmpListPath.m_nodes.pop_back();
             auto list = list_{std::get<listElement_>(attr.m_source.m_nodes.back().m_suffix).m_name};
-            parserContext.m_tmpListPath.m_nodes.push_back(dataNode_{attr.m_source.m_nodes.back().m_prefix, list});
+            parserContext.m_tmpListPath.m_nodes.emplace_back(attr.m_source.m_nodes.back().m_prefix, list);
 
             res = (space_separator >> listSuffix).parse(begin, end, ctx, rctx, listInstance);
             if (res) {