fix({Category,Country}ServiceImpl.findIdsWhenNameStartsWith): throw correct exception for invalid input.

Prior this change, UnknownFormatConversionException: Conversion = ''' was thrown instead of raised
IllegalArgumentException.

Found during work on #925

No functional changes.

Author: php-coder

src/main/java/ru/mystamps/web/feature/category/CategoryServiceImpl.java

@@ -106,7 +106,7 @@ public List<Integer> findIdsWhenNameStartsWith(String name) {
 		// FIXME: escape % and _ chars in name
 		Validate.isTrue(
 			!StringUtils.containsAny(name, '%', '_'),
-			"Name must not contain '%' or '_' chars"
+			"Name must not contain '%%' or '_' chars"
 		);
 
 		// converting to lowercase to perform a case-insensitive search

src/main/java/ru/mystamps/web/feature/country/CountryServiceImpl.java

@@ -106,7 +106,7 @@ public List<Integer> findIdsWhenNameStartsWith(String name) {
 		// FIXME: escape % and _ chars in name
 		Validate.isTrue(
 			!StringUtils.containsAny(name, '%', '_'),
-			"Name must not contain '%' or '_' chars"
+			"Name must not contain '%%' or '_' chars"
 		);
 
 		// converting to lowercase to perform a case-insensitive search