Update releasenotes/notes/sbplx_optimizer-a27361fc4ac8de8c.yaml

Author: woodsp-ibm

releasenotes/notes/sbplx_optimizer-a27361fc4ac8de8c.yaml

@@ -3,6 +3,6 @@ features:
   - |
     Support for SBPLX optimizer from NLopt library has been added.
     SBPLX is a local gradient-free optimizer based on Nelder-Mead and
-    is expected to show better convergence behaviour.
+    is expected to show better convergence behavior.
     Further information about this and all other optimizers can be found
     `in the API ref. here <https://qiskit-community.github.io/qiskit-algorithms/apidocs/qiskit_algorithms.optimizers.html>__`.