[zsh] Suppress error message when pipefail is not supported

Close #615

shell/key-bindings.zsh

@@ -8,7 +8,7 @@ __fsel() {
     -o -type f -print \
     -o -type d -print \
     -o -type l -print 2> /dev/null | sed 1d | cut -b3-"}"
-  setopt localoptions pipefail
+  setopt localoptions pipefail 2> /dev/null
   eval "$cmd | $(__fzfcmd) -m $FZF_CTRL_T_OPTS" | while read item; do
     echo -n "${(q)item} "
   done
@@ -35,7 +35,7 @@ bindkey '^T' fzf-file-widget
 fzf-cd-widget() {
   local cmd="${FZF_ALT_C_COMMAND:-"command find -L . \\( -path '*/\\.*' -o -fstype 'dev' -o -fstype 'proc' \\) -prune \
     -o -type d -print 2> /dev/null | sed 1d | cut -b3-"}"
-  setopt localoptions pipefail
+  setopt localoptions pipefail 2> /dev/null
   cd "${$(eval "$cmd | $(__fzfcmd) +m $FZF_ALT_C_OPTS"):-.}"
   local ret=$?
   zle reset-prompt
@@ -48,7 +48,7 @@ bindkey '\ec' fzf-cd-widget
 # CTRL-R - Paste the selected command from history into the command line
 fzf-history-widget() {
   local selected num
-  setopt localoptions noglobsubst pipefail
+  setopt localoptions noglobsubst pipefail 2> /dev/null
   selected=( $(fc -l 1 | eval "$(__fzfcmd) +s --tac +m -n2..,.. --tiebreak=index --toggle-sort=ctrl-r $FZF_CTRL_R_OPTS -q ${(q)LBUFFER}") )
   local ret=$?
   if [ -n "$selected" ]; then