[gui]修改SConscript文件,解决找不到"tjpgd.h"的问题

components/gui/libraries/tjpgd1a/SConscript

@@ -1,14 +1,13 @@
-Import('RTT_ROOT')
-Import('rtconfig')
 from building import *
+import rtconfig
 
+cwd = GetCurrentDir()
 src	= Split('''
 tjpgd.c
 ''')
 
-CPPPATH = [RTT_ROOT + '/components/external/tjpgd1a']
+CPPPATH = [cwd]
 
 group = DefineGroup('RTGUI', src, depend = ['RT_USING_GUIENGINE', 'RTGUI_IMAGE_TJPGD'], CPPPATH = CPPPATH)
 
-Return('group')
-
+Return('group')