Morphology plot: fix radial density of output synapses

This density plot became accidentally broken when introducing support
for desmosomes and gap junctions at the beginning of December in 2021
(ed78d6b). Instead of counting output synapses, all nodes where
taken into account.

Thanks to Gaspar Jekely for reporting this!

CHANGELOG.md

@@ -34,6 +34,8 @@
 - Connectivity widget: fix repeated 'syn count' header label in partner tables
   if 1000+ query skeletons are added to the widget.
 
+- Morphology plot: fix radial density of output synapses.
+
 ## 2021.12.21
 
 Contributors: Chris Barnes, Albert Cardona, Andrew Champion, Stephan Gerhard, Sanja Jasek, Tom Kazimiers

django/applications/catmaid/static/js/widgets/morphology-plot.js

@@ -349,6 +349,11 @@
           o[node] = positions[node];
           return o;
         }, {});
+      } else if (endsWith(this.mode, 'output synapses')) {
+        ps = line.connectors.reduce(function(o, row) {
+          if (0 === row[2]) o[row[0]] = positions[row[0]];
+          return o;
+        }, {});
       } else if (endsWith(this.mode, 'input synapses')) {
         ps = line.connectors.reduce(function(o, row) {
           if (1 === row[2]) o[row[0]] = positions[row[0]];