Unbreak win32 build

Commit de62a1096 broke win32 as it removed the HAVE_X11R6 checks for
building xim, but did not replace them with USE_X11. This made
it try to build xim on non-X targets.

modules/input/Makefile.am

@@ -30,11 +30,13 @@ im_xim_la_SOURCES = 		\
 	imxim.c
 libstatic_im_xim_la_SOURCES = $(im_xim_la_SOURCES)
 im_xim_la_LIBADD = $(LDADDS)
+if USE_X11
 if INCLUDE_IM_XIM
 STATIC_XIM_MODULE = libstatic-im-xim.la
 else
 XIM_MODULE=im-xim.la
 endif
+endif
 
 im_am_et_la_LDFLAGS = -rpath $(moduledir) -avoid-version -module $(no_undefined)
 im_am_et_la_SOURCES = imam-et.c