Redmine

here are my data:
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Environment:
Redmine version 2.5.2.stable
Ruby version 1.9.3-p547 (2014-05-14) [x86_64-linux]
Rails version 3.2.19
Environment production
Database adapter Mysql2
SCM:
Subversion 1.6.11
Git 1.7.1
Filesystem
Redmine plugins:
redmine_checklists 3.0.1
redmine_issue_status_change 1.0
redmine_theme_changer 0.1.0
redmine_xlsx_format_issue_exporter 0.1.0
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locale:
LANG=ru_RU.UTF-8
LC_CTYPE="ru_RU.UTF-8"
LC_NUMERIC="ru_RU.UTF-8"
LC_TIME="ru_RU.UTF-8"
LC_COLLATE="ru_RU.UTF-8"
LC_MONETARY="ru_RU.UTF-8"
LC_MESSAGES="ru_RU.UTF-8"
LC_PAPER="ru_RU.UTF-8"
LC_NAME="ru_RU.UTF-8"
LC_ADDRESS="ru_RU.UTF-8"
LC_TELEPHONE="ru_RU.UTF-8"
LC_MEASUREMENT="ru_RU.UTF-8"
LC_IDENTIFICATION="ru_RU.UTF-8"
LC_ALL=
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mysql> show variables like "character_set_database";
-----------------------------+ | Variable_name | Value |
-----------------------------+ | character_set_database | utf8 |
-----------------------------+
1 row in set (0.00 sec)
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But when I do exports to "Unified diff" is displayed as needed.
I attached two images so you can see them.
Please help me