Make command completion add space suffixes

Change-Id: I4cf6e35a4f896278cf492452c026434bfd080dce
diff --git a/src/ast_handlers.hpp b/src/ast_handlers.hpp
index c046040..04e890a 100644
--- a/src/ast_handlers.hpp
+++ b/src/ast_handlers.hpp
@@ -652,7 +652,7 @@
 
         parserContext.m_suggestions.clear();
         boost::mpl::for_each<CommandTypes, boost::type<boost::mpl::_>>([&parserContext](auto cmd) {
-            parserContext.m_suggestions.insert({commandNamesVisitor()(cmd)});
+            parserContext.m_suggestions.insert({commandNamesVisitor()(cmd), " "});
         });
     }
 };