JS error when showing/hiding feedback on non existent elements

[bartekch]

If we call hideFeedback or showFeedback* with inputId of nonexistent element, a JS error is throw like on the screen below.

This is NOT causing any issues in Shiny app itself, so it has little importance, but I'm bringing this up anyway since it may surprise someone checking the console.

Example

library(shiny)
library(shinyFeedback)
shinyApp(
  ui = basicPage(
    shinyFeedback::useShinyFeedback(),
    actionButton("b", "Throw JS error")
  ),
  
  server = function(input, output, session) {
    observe({
      input$b
      shinyFeedback::hideFeedback("input")
      shinyFeedback::showFeedbackSuccess("input")
    })
  }
)

Checked with version 5cc4d16