Slight word usage and grammar error in the openib btl help test. I

believe the change below is the intended meaning.

This commit was SVN r16921.

ompi/mca/btl/openib/help-mpi-btl-openib.txt

@@ -164,7 +164,7 @@ respect to the retry count:
   See the InfiniBand spec 1.2 (section 12.7.34) for more details.
 #
 [no active ports found]
-WARNING: There is at least on IB HCA found on host '%s', but there is
+WARNING: There is at least one IB HCA found on host '%s', but there are
 no active ports detected. This is most certainly not what you wanted.
 Check your cables and SM configuration.
 #