fix(strainsyn.go): correct nil check to prevent potential null pointe…

…r exception

The nil check was previously checking the 'Data' field of the 'tac'
object. However, if 'tac' itself was null, this would result in a null
pointer exception. The nil check has been corrected to check 'tac'
instead of 'tac.Data', preventing potential crashes due to null pointer
exceptions.

internal/load/stockcenter/strainsyn.go

@@ -84,7 +84,7 @@ func removeExistingSynonyms(
 	if err != nil && status.Code(err) != codes.NotFound {
 		return fmt.Errorf("error in listing synonyms for %s %s", entryId, err)
 	}
-	if tac.Data == nil {
+	if tac == nil {
 		logger.Debugf("synonym %s is absent, no need to remove it", entryId)
 		return nil
 	}