Make license rule a clue

Reference: #3480
Signed-off-by: Ayan Sinha Mahapatra <ayansmahapatra@gmail.com>

Author: AyanSinhaMahapatra

src/licensedcode/data/rules/unknown-license-reference_332.RULE

@@ -1,6 +1,6 @@
 ---
 license_expression: unknown-license-reference
-is_license_reference: yes
+is_license_clue: yes
 relevance: 80
 ---