documentation: Cleanup formatting in gerrit-config

Some of our formatting style was not consistent.

Change-Id: I7bedb9ffc5f691ac66c5974053b52a28a21003b6
Signed-off-by: Shawn O. Pearce <sop@google.com>

Documentation/config-gerrit.txt

@@ -529,14 +529,14 @@ much more predictable behavior.
 The database section configures where Gerrit stores its metadata
 records about user accounts and change reviews.
 
-====
+----
 [database]
   type = postgres
   hostname = localhost
   database = reviewdb
   username = gerrit2
   password = s3kr3t
-====
+----
 
 [[database.type]]database.type::
 +
@@ -649,16 +649,19 @@ For example, "?p=$project.git;h=$commit".
 ~~~~~~~~~~~~~~~~~~~~
 
 [[http.proxy]]http.proxy::
++
 URL of the proxy server when making outgoing HTTP
 connections for OpenID login transactions.  Syntax
 should be `http://`'hostname'`:`'port'.
 
 [[http.proxyUsername]]http.proxyUsername::
++
 Optional username to authenticate to the HTTP proxy with.
 This property is honored only if the username does not 
 appear in the http.proxy property above.
 
 [[http.proxyPassword]]http.proxyPassword::
++
 Optional password to authenticate to the HTTP proxy with.
 This property is honored only if the password does not 
 appear in the http.proxy property above.
@@ -753,10 +756,10 @@ and private key.  This keystore is required for `https://` in URL.
 +
 To create a self-signed certificate for simple internal usage:
 +
-====
+----
 keytool -keystore keystore -alias jetty -genkey -keyalg RSA
 chmod 600 keystore
-====
+----
 +
 If not absolute, the path is resolved relative to `$site_path`.
 +
@@ -817,18 +820,18 @@ detected during startup.  The guessed defaults support both
 link:http://www.ietf.org/rfc/rfc2307.txt[RFC 2307] and Active
 Directory.
 
-====
+----
 [ldap]
   server = ldap://ldap.example.com
-    #
+
   accountBase = ou=people,dc=example,dc=com
   accountPattern = (&(objectClass=person)(uid=${username}))
   accountFullName = displayName
   accountEmailAddress = mail
-    #
+
   groupBase = ou=groups,dc=example,dc=com
   groupMemberPattern = (&(objectClass=group)(member=${dn}))
-====
+----
 
 [[ldap.server]]ldap.server::
 +
@@ -1019,16 +1022,19 @@ or the wildcard `\*/*` to match all types.
 By default, false for all MIME types.
 
 Common examples:
-====
+----
 [mimetype "image/*"]
   safe = true
+
 [mimetype "application/pdf"]
   safe = true
+
 [mimetype "application/msword"]
   safe = true
+
 [mimetype "application/vnd.ms-excel"]
   safe = true
-====
+----
 
 [[repo]]Section repo
 ~~~~~~~~~~~~~~~~~~~~