Invalid output of --suggest option

[treiher]

Describe the bug
The output of the --suggest option contains too many quotes after the --steps option.

Console Output

Warning: You requested a suggested prover configuration.
Warning: This feature is highly experimental.
Warning: Please consult the documentation.

package Prove is
   for Prover_Switches ("sparknacl-car.adb") use ("--provers=CVC4", "--steps=5882"", "--timeout=1");