wscript: fix stdin input wasn't enabled for dedicated. Fix single-binary help string

engine/wscript

@@ -39,7 +39,8 @@ def configure(conf):
 		conf.options.USE_SELECT = conf.options.DEDICATED
 
 	conf.define_cond('SINGLE_BINARY', conf.env.SINGLE_BINARY)
-	conf.define_cond('XASH_USE_SELECT', conf.options.USE_SELECT)
+
+	conf.define_cond('XASH_USE_SELECT', conf.options.USE_SELECT or conf.options.DEDICATED)
 	conf.define_cond('SUPPORT_BSP2_FORMAT', conf.options.SUPPORT_BSP2_FORMAT)
 	conf.define_cond('XASH_64BIT', conf.env.DEST_SIZEOF_VOID_P != 4)
 	conf.define_cond('DBGHELP', conf.env.DEST_OS == 'win32')

wscript

@@ -47,7 +47,7 @@ def options(opt):
 		help = 'build Xash Dedicated Server [default: %default]')
 
 	grp.add_option('--single-binary', action = 'store_true', dest = 'SINGLE_BINARY', default = False,
-		help = 'build single "xash" binary [default: %default]')
+		help = 'build single "xash" binary (always enabled for dedicated) [default: %default]')
 
 	grp.add_option('-8', '--64bits', action = 'store_true', dest = 'ALLOW64', default = False,
 		help = 'allow targetting 64-bit engine(Linux/Windows/OSX x86 only) [default: %default]')