build: add missing header to Makefile.am
PR:
@@ -4,5 +4,5 @@ SUBDIRS=widget
pkginclude_HEADERS = widget_base.h widget_task.h widget_prototype.h \
widget_style.h widget_event.h widget_paint.h widget.h css_library.h \
widget_helper.h css_parser.h css_rule_font_face.h css_fontstyle.h \
-builder.h metrics.h
+builder.h metrics.h widget_layout.h
pkgincludedir=$(prefix)/include/LCUI/gui
