bump reva 2.28

vendor/github.com/prometheus/alertmanager/pkg/labels/matcher.go

@@ -205,7 +205,7 @@ func (ms Matchers) String() string {
 	return buf.String()
 }
 
-// This is copied from matchers/parse/lexer.go. It will be removed when
+// This is copied from matcher/parse/lexer.go. It will be removed when
 // the transition window from classic matchers to UTF-8 matchers is complete,
 // as then we can use double quotes when printing the label name for all
 // matchers. Until then, the classic parser does not understand double quotes

vendor/github.com/prometheus/alertmanager/pkg/labels/parse.go

@@ -136,7 +136,7 @@ func ParseMatcher(s string) (_ *Matcher, err error) {
 		return nil, fmt.Errorf("matcher value not valid UTF-8: %s", ms[3])
 	}
 
-	// Unescape the rawValue:
+	// Unescape the rawValue.
 	for i, r := range rawValue {
 		if escaped {
 			escaped = false