[bash] Fall back to send-keys if named paste buffer is not supported

Related: #616

shell/key-bindings.bash

@@ -26,7 +26,7 @@ __fzf_select_tmux__() {
     height="-l $height"
   fi
 
-  tmux split-window $height "cd $(printf %q "$PWD"); FZF_DEFAULT_OPTS=$(printf %q "$FZF_DEFAULT_OPTS") PATH=$(printf %q "$PATH") FZF_CTRL_T_COMMAND=$(printf %q "$FZF_CTRL_T_COMMAND") FZF_CTRL_T_OPTS=$(printf %q "$FZF_CTRL_T_OPTS") bash -c 'source \"${BASH_SOURCE[0]}\"; tmux setb -b \"fzf\" \"\$(__fzf_select__)\"; tmux pasteb -b \"fzf\" -t $TMUX_PANE; tmux deleteb -b \"fzf\"'"
+  tmux split-window $height "cd $(printf %q "$PWD"); FZF_DEFAULT_OPTS=$(printf %q "$FZF_DEFAULT_OPTS") PATH=$(printf %q "$PATH") FZF_CTRL_T_COMMAND=$(printf %q "$FZF_CTRL_T_COMMAND") FZF_CTRL_T_OPTS=$(printf %q "$FZF_CTRL_T_OPTS") bash -c 'source \"${BASH_SOURCE[0]}\"; RESULT=\"\$(__fzf_select__)\"; tmux setb -b fzf \"\$RESULT\" \\; pasteb -b fzf -t $TMUX_PANE \\; deleteb -b fzf || tmux send-keys -t $TMUX_PANE \"\$RESULT\"'"
 }
 
 fzf-file-widget() {