ccmake: Extend clear line.

When configuring or generating the 'ng' of the end of the second line
is not cleared.  This patch fixes this.

The problem was introduced by commit fd632195 (ccmake: Align 'g' and 'q'
key instructions, 2011-01-07) which adjusted the length of lines that
need clearing.

Source/CursesDialog/cmCursesMainForm.cxx

@@ -410,7 +410,7 @@ void cmCursesMainForm::PrintKeys(int process /* = 0 */)
   if (process)
     {
     const char* clearLine =
-      "                                                               ";
+      "                                                                    ";
     strcpy(firstLine, clearLine);
     strcpy(secondLine, clearLine);
     strcpy(thirdLine, clearLine);