Revert "Add simple master key provider for secret encryption"

This reverts commit d4e84c0433.

options/locale/locale_en-US.ini

@@ -185,12 +185,6 @@ app_url_helper = Base address for HTTP(S) clone URLs and email notifications.
 log_root_path = Log Path
 log_root_path_helper = Log files will be written to this directory.
 
-security_title = Security Settings
-master_key_provider = Master Key Provider
-master_key_provider_none = None
-master_key_provider_plain = Plain
-master_key_provider_helper = Master Key Provider to use to store secret key that will be used for other secret encryption. Use "None" to not encrypt secrets. Use "Plain" to store automatically generated secret in configuration file.
-
 optional_title = Optional Settings
 email_title = Email Settings
 smtp_addr = SMTP Host
@@ -251,7 +245,6 @@ password_algorithm = Password Hash Algorithm
 password_algorithm_helper = Set the password hashing algorithm. Algorithms have differing requirements and strength. `argon2` whilst having good characteristics uses a lot of memory and may be inappropriate for small systems.
 enable_update_checker = Enable Update Checker
 enable_update_checker_helper = Checks for new version releases periodically by connecting to gitea.io.
-master_key_failed = Failed to generate master key: %v
 
 [home]
 uname_holder = Username or Email Address
@@ -473,7 +466,6 @@ max_size_error = ` must contain at most %s characters.`
 email_error = ` is not a valid email address.`
 url_error = `'%s' is not a valid URL.`
 include_error = ` must contain substring '%s'.`
-in_error = ` can contain only specific values: %s.`
 glob_pattern_error = ` glob pattern is invalid: %s.`
 regex_pattern_error = ` regex pattern is invalid: %s.`
 username_error = ` can only contain alphanumeric chars ('0-9','a-z','A-Z'), dash ('-'), underscore ('_') and dot ('.'). It cannot begin or end with non-alphanumeric chars, and consecutive non-alphanumeric chars are also forbidden.`