Fixed compilation problem with WS_INDICATOR defined.

ChangeLog

@@ -4,6 +4,7 @@ Changes since version 0.60.0:
 - fixed some problems with non gcc compilers.
 - fixed problem with showing instance.class in the inspector window.
 - fixed crash when displaying workspace name in some positions.
+- fixed compilation problem when WS_INDICATOR was defined.
 
 
 Changes since version 0.53.0:

NEWS

@@ -95,7 +95,7 @@ This entry will work in the following way, depending on the context:
    while the ones that will fail for some reason to gain their new state,
    will remain selected.
 
-In both cases if there is not success in setting what user requested a panel
+In both cases if there is no success in setting what user requested a panel
 will inform user of the failure.
 (Note: trying to set an icon to not-omnipresent will never fail. Failures can
        be met only when trying to set omnipresent for an icon).

src/appicon.c

@@ -47,6 +47,8 @@
 #ifdef XDND
 #include "xdnd.h"
 #endif
+#include "WINGsP.h"
+
 
 /*
  * icon_file for the dock is got from the preferences file by