also set rust_src_path, probably redundant

vimrc

@@ -452,5 +452,7 @@ map <F10> :echo "hi<" . synIDattr(synID(line("."),col("."),1),"name") . '> trans
 
 let g:rustfmt_autosave = 1
 let g:ycm_rust_src_path = $RUST_SRC_PATH
+let g:rust_src_path = $RUST_SRC_PATH
 autocmd BufRead *.rs :setlocal tags=./rusty-tags.vi;/,$RUST_SRC_PATH/rusty-tags.vi
 autocmd BufWrite *.rs :silent! exec "!rusty-tags vi --quiet --start-dir=" . expand('%:p:h') . "&" <bar> redraw!
+