Don't output empty fields.

src/main.cpp

@@ -111,9 +111,18 @@ int main(int argc, char *argv[])
 
                 for (const auto &match : search::search(filepath, regex, opts))
                 {
-                    cout << match.filepath << ", " << match.headline << ", "
-                         << match.page << ": " << match.context.first
-                         << match.text << match.context.second << '\n';
+                    cout << match.filepath;
+                    if (!match.headline.empty())
+                    {
+
+                        cout << ", " << match.headline;
+                    }
+                    if (!match.page.empty())
+                    {
+                        cout << ", " << match.page;
+                    }
+                    cout << ": " << match.context.first << match.text
+                         << match.context.second << '\n';
                 }
             }
         }