chore(inputs): Remove unnecessary nil check (#13749)

Signed-off-by: Eng Zer Jun <engzerjun@gmail.com>

plugins/inputs/prometheus/prometheus.go

@@ -410,11 +410,9 @@ func (p *Prometheus) gatherURL(u URLAndAddress, acc telegraf.Accumulator) error
 		req.SetBasicAuth(p.Username, p.Password)
 	}
 
-	if p.HTTPHeaders != nil {
 	for key, value := range p.HTTPHeaders {
 		req.Header.Set(key, value)
 	}
-	}
 
 	var resp *http.Response
 	if u.URL.Scheme != "unix" {

plugins/inputs/vsphere/endpoint.go

@@ -1388,13 +1388,11 @@ func (e *Endpoint) populateTags(objectRef *objectRef, resourceType string, resou
 	}
 
 	// Fill in custom values if they exist
-	if objectRef.customValues != nil {
 	for k, v := range objectRef.customValues {
 		if v != "" {
 			t[k] = v
 		}
 	}
-	}
 }
 
 func (e *Endpoint) makeMetricIdentifier(prefix, metric string) (metricName string, fieldName string) {