wendelin_telecom_base: Improve KPI calculation robustness

Improve error handling and reduce chunk size

bt5/wendelin_telecom_base/ExtensionTemplateItem/portal_components/extension.erp5.OrsKpiUtils.py

@@ -13,6 +13,9 @@ def load_measurements(alogm):
         # Invalid measurement: simply skip it
         pass
       measurement = alogm.read()
+  except amari_kpi.LogError:
+    # Invalid measurement: simply skip it
+    pass
   finally:
     alogm.close()
   return mlog

bt5/wendelin_telecom_base/PathTemplateItem/portal_callables/DataAnalysisLine_calculateOrsKpi.py

@@ -8,7 +8,7 @@ total_size = in_data_stream.getSize()
 if start >= total_size:
   return
 
-chunk_size = 1024 * 1024
+chunk_size = 512 * 512
 end = min(start + chunk_size, total_size)
 
 log_data = ''.join(in_data_stream.readChunkList(start, end))