Don't test for XTest when not using X11 wxUIActionSimulator

There is no need to check (and give a warning about it being not found) when
building wxMSW, wxOSX or even wxQt.

configure

@@ -33569,6 +33569,7 @@ if test "$wxUSE_UIACTIONSIMULATOR" = "yes" ; then
     $as_echo "#define wxUSE_UIACTIONSIMULATOR 1" >>confdefs.h
 
     SAMPLES_SUBDIRS="$SAMPLES_SUBDIRS uiaction"
+    if test "$wxUSE_GTK" = 1 -o "$wxUSE_MOTIF" = 1 -o "$wxUSE_X11" = 1; then
         if test "$wxUSE_XTEST" = "yes" ; then
 
 pkg_failed=no
@@ -33656,6 +33657,7 @@ $as_echo "yes" >&6; }
 
 fi
         fi
+    fi
 fi
 
 if test "$wxUSE_DC_TRANSFORM_MATRIX" = "yes" ; then

configure.in

@@ -6361,6 +6361,7 @@ fi
 if test "$wxUSE_UIACTIONSIMULATOR" = "yes" ; then
     AC_DEFINE(wxUSE_UIACTIONSIMULATOR)
     SAMPLES_SUBDIRS="$SAMPLES_SUBDIRS uiaction"
+    if test "$wxUSE_GTK" = 1 -o "$wxUSE_MOTIF" = 1 -o "$wxUSE_X11" = 1; then
         if test "$wxUSE_XTEST" = "yes" ; then
             PKG_CHECK_MODULES(XTST, xtst,
                 [
@@ -6375,6 +6376,7 @@ if test "$wxUSE_UIACTIONSIMULATOR" = "yes" ; then
                 ]
             )
         fi
+    fi
 fi
 
 if test "$wxUSE_DC_TRANSFORM_MATRIX" = "yes" ; then