debian/source/lintian-overrides: update override to match false-positive

Author: terceiro

debian/source/lintian-overrides

@@ -1,4 +1,3 @@
 source-contains-prebuilt-ms-help-file
 # There is no RFC text
-license-problem-non-free-RFC .bundle/gems/net-imap-0.4.9.1/LICENSE.txt
-license-problem-non-free-RFC-BCP78 [.bundle/gems/net-imap-0.4.9.1/LICENSE.txt]
+license-problem-non-free-RFC [.bundle/gems/net-imap-0.4.9.1/LICENSE.txt]