Update contributed_definitions/NXstress.nxdl.xml

Change back again the angstrom symbol

contributed_definitions/NXstress.nxdl.xml

@@ -1009,7 +1009,8 @@
 
                             - if *center_type="two-theta"* then *cUnit* must have the angle unit *degrees*
                             - if *center_type="energy"* then *cUnit* must have the unit *keV*
-                            - if *center_type="momentum-transfer"* then *cUnit* must have the unit \ :math:`\unicode{x212B}^{-1}`
+                            - if *center_type="momentum-transfer"* then *cUnit* must have the unit \ :math:`Å^{-1}`^{-1}`
+
                             - if *center_type="d-spacing"* then *cUnit* must have the unit \ :math:`\unicode{x212B}`
                             - if *center_type="channel"* then *cUnit* must be *dimensioness*
                             - if *center_type="time-of-flight"* then *cUnit* must have the unit \ :math:`\mu\mathrm{s}`