opal/configury: allow param usage multiple times

Turns out the OPAL_FLAGS_UNIQ function was chopping
off multiple instances of --param when set in the
CFLAGS.  This can happen when -mnative or other machine
target is specified as part of CFLAGS.

Thanks to QuesarVII for reporting this and supplying a patch.

Fixes #324

config/opal_functions.m4

@@ -399,6 +399,10 @@ AC_DEFUN([OPAL_FLAGS_UNIQ],[
                 opal_found=0
                 opal_i=`expr $opal_count + 1`
                 ;;
+        --param)
+                ompi_found=0
+                ompi_i=`expr $ompi_count + 1`
+                ;;
         esac
 
         # If we didn't find the token, add it to the "array"