removed symbols that supposed to be URL-encoded from alphabet
removed symbols that supposed to be URL-encoded from alphabet

tectronics/slowhttptest,yeahdongcn/slowhttptest,mfazliazran/slowhttptest,mentesc/slowhttptest,Chigirin/slowhttptest,mentesc/slowhttptest,0x37N0w4N/slowhttptest,yeahdongcn/slowhttptest,0x37N0w4N/slowhttptest,jengyic/slowhttptest,jack-ju/slowhttptest,tectronics/slowhttptest,jengyic/slowhttptest,a12689851/slowhttptest,mfazliazran/slowhttptest,Chigirin/slowhttptest,a12689851/slowhttptest,jack-ju/slowhttptest