gnu: tor: Fix typo.

* gnu/packages/tor.scm (tor)[inputs]: Move unquote to its operand.

gnu/packages/tor.scm

@@ -62,7 +62,7 @@ (define-public tor
      `(("zlib" ,zlib)
        ("openssl" ,openssl)
        ("libevent" ,libevent)
-       ("libseccomp", libseccomp)))
+       ("libseccomp" ,libseccomp)))
     (home-page "https://www.torproject.org/")
     (synopsis "Anonymous network router to improve privacy on the Internet")
     (description