gnu: openmpi: Fix typo in download uri

* gnu/packages/mpi.scm (openmpi)[origin]: Fix typo.

gnu/packages/mpi.scm

@@ -32,7 +32,7 @@ (define-public openmpi
     (source
      (origin
       (method url-fetch)
-      (uri (string-append "http://www.open-mpi.org/softawre/ompi/v"
+      (uri (string-append "http://www.open-mpi.org/software/ompi/v"
                           (string-join (take (string-split version #\.) 2)
                                        ".")
                           "/downloads/openmpi-" version ".tar.bz2"))