Add new overload for transmissibilityBoundary() without element context.

ebos/eclproblem.hh

@@ -1340,6 +1340,15 @@ public:
         return transmissibilities_.transmissibilityBoundary(elemIdx, boundaryFaceIdx);
     }
 
+    /*!
+     * \brief Direct access to a boundary transmissibility.
+     */
+    Scalar transmissibilityBoundary(const unsigned globalSpaceIdx,
+                                    const unsigned boundaryFaceIdx) const
+    {
+        return transmissibilities_.transmissibilityBoundary(globalSpaceIdx, boundaryFaceIdx);
+    }
+
     /*!
      * \copydoc EclTransmissiblity::thermalHalfTransmissibility
      */