scummvm: don't hardcode the "extrapath" at runtime

In order to allow users to change the 'extrapath' directory, don't add the 'extrapath' parameter unless it's missing from the configuration file.
Note that multiple 'extrapath' entries can be present in the configuration file, since it can be set per-game as well as a global option.

Author: cmitu

scriptmodules/emulators/scummvm.sh

@@ -86,7 +86,10 @@ function configure_scummvm() {
 #!/bin/bash
 game="\$1"
 pushd "$romdir/scummvm" >/dev/null
-$md_inst/bin/scummvm --fullscreen --joystick=0 --extrapath="$md_inst/extra" "\$game"
+if ! grep -qs extrapath "\$HOME/.config/scummvm/scummvm.ini"; then
+    params="--extrapath="$md_inst/extra""
+fi
+$md_inst/bin/scummvm --fullscreen \$params --joystick=0 "\$game"
 while read id desc; do
     echo "\$desc" > "$romdir/scummvm/\$id.svm"
 done < <($md_inst/bin/scummvm --list-targets | tail -n +3)