[master] adjusted cppcheck filter to suppress a false alarm about a template file.

trivial, directly pushing the fix.

src/cppcheck-suppress.lst

@@ -3,7 +3,7 @@
 debug
 missingInclude
 // This is a template, and should be excluded from the check
-unreadVariable:src/lib/dns/rdata/template.cc:60
+unreadVariable:src/lib/dns/rdata/template.cc:61
 // Intentional self assignment tests.  Suppress warning about them.
 selfAssignment:src/lib/dns/tests/name_unittest.cc:293
 selfAssignment:src/lib/dns/tests/rdata_unittest.cc:228