Update CHANGELOG.md

fixed changelog PR number

Signed-off-by: Gemma Fardell <47746591+gfardell@users.noreply.github.com>

Author: gfardell

CHANGELOG.md

@@ -2,7 +2,7 @@
 * 24.1.0
   - New Features:
     - Added method to plot filter in `GenericFilteredBackProjection` (#1667)
-    - Added wavelet operator, wrapping PyWavelets operator as a CIL operator (#1618)
+    - Added wavelet operator, wrapping PyWavelets operator as a CIL operator (#1615)
     - Added PaganinProcessor processor, to perform phase retrieval from phase contrast images (#1737)
     - Added L1Sparsity function, allowing calculations of `|Ax-b|_1` and its proximal, in the case of orthogonal operators, `A` (#1618)
     - Options in algorithms GD, ISTA and FISTA to pass a `cil.optimisation.utilities.StepSizeRule` or a `cil.optimisation.utilities.Preconditioner`(#1768)