In #14248 a new image was added to represent Euler's Number. Running
optipng on the image results in a smaller file size but causes
calculator to throw the following error message:
Calculator(39:39): Exiting with runtime error: PNGImageDecoderPlugin:
Palette index out of range.
This commit provides a fixed image file.
This is meant to address #14234 by renaming the "Euler's Constant"
menu item to "Euler's Number". This commit removes the existing
"eulers.png" and replaces with a new "eulers_number.png" for clarity.
