l10n: Eliminated some column labels

src/commands/CmdBurndown.cpp

@@ -397,7 +397,7 @@ std::string Chart::render ()
   }
 
   if (_max_value == 0)
-    context.footnote (STRING_FEEDBACK_NO_MATCH);
+    context.footnote ("No matches.");
 
   // Create a grid, folded into a string.
   _grid = "";

src/commands/CmdCustom.cpp

@@ -229,7 +229,7 @@ int CmdCustom::execute (std::string& output)
   }
   else
   {
-    context.footnote (STRING_FEEDBACK_NO_MATCH);
+    context.footnote ("No matches.");
     rc = 1;
   }