Fixed the order of cluster.data being incorrect (#221)

While using the cluster finder and saving a cluster, pixels which are
out of bounds are skipped. cluster.data should contain the pedestal
corrected ADU information of each pixel.

However, the counter "i" which keeps track of the position of
cluster.data is only incremented if the pixel was inside the bounds of
the frame.

This means that any clusters close to the frame's edges are not
construed properly. This means that if you want to extract a 3x3 from a
9x9 cluster, it can fail if the cluster data is not properly centered in
the pixel.

Fixed by moving i++ outside the bounds check.

Co-authored-by: Jonathan Mulvey <jonathan.mulvey@psi.ch>

include/aare/ClusterFinder.hpp

@@ -144,9 +144,9 @@ class ClusterFinder {
                                     static_cast<CT>(
                                         m_pedestal.mean(iy + ir, ix + ic));
                                 cluster.data[i] =
-                                    tmp; // Watch for out of bounds access
-                                i++;
+                                    tmp; // Watch for out of bounds access                                
                             }
+                            i++;
                         }
                     }