Work around LGTM errors: Clear-text logging of sensitive information

Disable false positives that cannot be fixed by LGTM, because their
heuristic detects strings such "id" that are actually very common in
DICOM, for example in "UID".

lgtm.yml

@@ -0,0 +1,4 @@
+---
+queries:
+  # https://lgtm.com/rules/1510014536001/
+  - exclude: py/clear-text-logging-sensitive-data