[TkAl][PixBary][FIX] PixelBarycentreAnalyzer: do not try to guess the label

Using the title to guess caused a ConfigFileReadError when it was missing

Author: amecca

Alignment/OfflineValidation/python/TkAlAllInOneTool/PixelBaryCentreAnalyzer_cfg.py

@@ -126,7 +126,7 @@
 alignments = configuration.get('alignments', None) # NOTE: aligments is plural
 if alignments is None:
     align = configuration['alignment'] # NOTE: alignment is singular
-    label = configuration['alignment'].get('label', align['title'].split()[0])
+    label = configuration['alignment'].get('label', 'alignment')
     alignments = {label: align}
 
 for label, align in alignments.items():