csgrep --warning-rate-limit: fix key events out of range

Related: https://issues.redhat.com/browse/OSH-67
Closes: #145

Author: kdudka

src/lib/filter.cc

@@ -249,6 +249,7 @@ bool RateLimitter::matchDef(const Defect &def)
         evt.msg.clear();
 
         Defect defProto = def;
+        defProto.keyEventIdx = 0U;
         defProto.events.clear();
         defProto.events.push_back(std::move(evt));
         d->errors.push(std::move(defProto));

tests/csgrep/0116-csgrep-warning-rate-limit-args.txt

@@ -0,0 +1 @@
+--mode=json --warning-rate-limit=1