Fix checks compiling

include/theme.h

@@ -410,8 +410,10 @@ Property *rofi_theme_find_property ( ThemeWidget *widget, PropertyType type, con
  */
 gboolean rofi_theme_is_empty ( void );
 
+#ifdef THEME_CONVERTER
 /**
  * Convert old theme colors into default one.
  */
 void rofi_theme_convert_old ( void );
 #endif
+#endif

source/theme.c

@@ -574,6 +574,8 @@ gboolean rofi_theme_is_empty ( void )
     return FALSE;
 }
 
+#ifdef THEME_CONVERTER
+
 void rofi_theme_convert_old ( void )
 {
     if ( config.color_window ) {
@@ -639,3 +641,4 @@ void rofi_theme_convert_old ( void )
         g_strfreev ( retv );
     }
 }
+#endif // THEME_CONVERTER