refactoring

application/src/main/java/org/thingsboard/server/service/security/system/DefaultSystemSecurityService.java

@@ -175,7 +175,7 @@ public class DefaultSystemSecurityService implements SystemSecurityService {
         if (isPositiveInteger(passwordPolicy.getMinimumSpecialCharacters())) {
             passwordRules.add(new CharacterRule(EnglishCharacterData.Special, passwordPolicy.getMinimumSpecialCharacters()));
         }
-        if (!passwordPolicy.getAllowWhitespaces()) {
+        if (passwordPolicy.getAllowWhitespaces() != null && !passwordPolicy.getAllowWhitespaces()) {
             passwordRules.add(new WhitespaceRule());
         }
         PasswordValidator validator = new PasswordValidator(passwordRules);

common/data/src/main/java/org/thingsboard/server/common/data/security/model/UserPasswordPolicy.java

@@ -35,7 +35,7 @@ public class UserPasswordPolicy implements Serializable {
     private Integer minimumDigits;
     @ApiModelProperty(position = 1, value = "Minimum number of special in the password." )
     private Integer minimumSpecialCharacters;
-    @ApiModelProperty(position = 1, value = "Allow white-spaces")
+    @ApiModelProperty(position = 1, value = "Allow whitespaces")
     private Boolean allowWhitespaces = true;
 
     @ApiModelProperty(position = 1, value = "Password expiration period (days). Force expiration of the password." )