remove label match operator from keyword.operator

public/app/plugins/datasource/prometheus/mode-prometheus.js

@@ -46,7 +46,7 @@ var PrometheusHighlightRules = function() {
       regex : "[a-zA-Z_$][a-zA-Z0-9_$]*\\b"
       regex : "[a-zA-Z_$][a-zA-Z0-9_$]*\\b"
     }, {
     }, {
       token : "keyword.operator",
       token : "keyword.operator",
-      regex : "\\+|\\-|\\*|\\/|%|\\^|=|==|!=|<=|>=|<|>"
+      regex : "\\+|\\-|\\*|\\/|%|\\^|==|!=|<=|>=|<|>"
     }, {
     }, {
       token : "paren.lparen",
       token : "paren.lparen",
       regex : "[[(]"
       regex : "[[(]"