fix: login shell path interpreted as string by modern shells

The single quotes around the login shell path are interpreted as string by modern shells like nushell.
The exec call breaks.

Tested locally with nushell.

Fixes: #221

data/start-cosmic

@@ -24,7 +24,7 @@ if [ -n "${SHELL}" ]; then
     # --in-login-shell: our flag to indicate that we don't need to recurse any further
     if [ "${1}" != "--in-login-shell" ]; then
         # `-l`: start $SHELL as a login shell so it sources the user's profile.
-        exec "${SHELL}" -l -c "'${0}' --in-login-shell"
+        exec "${SHELL}" -l -c "${0} --in-login-shell"
     fi
 fi