doc: drop backslash quoting of some curly braces

Text like "{foo}" triggers an AsciiDoc attribute; we have to
write "\{foo}" to suppress this. But when the "foo" is not a
syntactically valid attribute, we can skip the quoting. This
makes the source nicer to read, and looks better under
Asciidoctor. With AsciiDoc itself, this patch produces no
changes.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/gitremote-helpers.txt

@@ -408,22 +408,22 @@ set by Git if the remote helper has the 'option' capability.
 	of <n> correspond to the number of -v flags passed on the
 	command line.
 
-'option progress' \{'true'|'false'\}::
+'option progress' {'true'|'false'}::
 	Enables (or disables) progress messages displayed by the
 	transport helper during a command.
 
 'option depth' <depth>::
 	Deepens the history of a shallow repository.
 
-'option followtags' \{'true'|'false'\}::
+'option followtags' {'true'|'false'}::
 	If enabled the helper should automatically fetch annotated
 	tag objects if the object the tag points at was transferred
 	during the fetch command.  If the tag is not fetched by
 	the helper a second fetch command will usually be sent to
 	ask for the tag specifically.  Some helpers may be able to
 	use this option to avoid a second network connection.
 
-'option dry-run' \{'true'|'false'\}:
+'option dry-run' {'true'|'false'}:
 	If true, pretend the operation completed successfully,
 	but don't actually change any repository data.	For most
 	helpers this only applies to the 'push', if supported.
@@ -434,18 +434,18 @@ set by Git if the remote helper has the 'option' capability.
 	must not rely on this option being set before
 	connect request occurs.
 
-'option check-connectivity' \{'true'|'false'\}::
+'option check-connectivity' {'true'|'false'}::
 	Request the helper to check connectivity of a clone.
 
-'option force' \{'true'|'false'\}::
+'option force' {'true'|'false'}::
 	Request the helper to perform a force update.  Defaults to
 	'false'.
 
-'option cloning \{'true'|'false'\}::
+'option cloning {'true'|'false'}::
 	Notify the helper this is a clone request (i.e. the current
 	repository is guaranteed empty).
 
-'option update-shallow \{'true'|'false'\}::
+'option update-shallow {'true'|'false'}::
 	Allow to extend .git/shallow if the new refs require it.
 
 SEE ALSO