Fix for null columns in books.language crash

utils/sql/db_update_manifest.txt

@@ -356,6 +356,7 @@
 9100|2016_08_27_object_display_name.sql|SHOW COLUMNS FROM `object` LIKE 'display_name'|empty|
 9101|2016_12_01_pcnpc_only.sql|SHOW COLUMNS FROM `spells_new` LIKE 'pcnpc_only_flag'|empty|
 9102|2017_01_10_book_languages.sql|SHOW COLUMNS FROM `books` LIKE 'language'|empty|
+9103|2017_01_30_book_languages_fix.sql|SELECT `language` from `books` WHERE `language` IS NULL|not_empty|
 
 # Upgrade conditions:
 # 	This won't be needed after this system is implemented, but it is used database that are not

utils/sql/git/required/2017_01_10_book_languages.sql

@@ -1,4 +1,4 @@
-alter table books add language int default 0;
+alter table books add language int not null default 0;
 
 drop table if exists reading_is_fundamental;
 

utils/sql/git/required/2017_01_30_book_languages_fix.sql

@@ -0,0 +1,4 @@
+UPDATE `books` SET `language` = '0' WHERE `language` IS NULL;
+
+ALTER TABLE `books` MODIFY COLUMN `language` INT NOT NULL DEFAULT '0';
+