Avoid extra whitespace in the arguments of <indexterm>.

As noted by Thom Brown, this confuses the DocBook index processor; it
fails to merge entries that differ only in whitespace, and sorts them
unexpectedly as well.  Seems like a toolchain bug, but I'm not going to
hold my breath waiting for a fix.

Note: easiest way to find these is to look for double spaces in HTML.index.

doc/src/sgml/runtime.sgml

@@ -142,8 +142,11 @@ postgres$ <userinput>initdb -D /usr/local/pgsql/data</userinput>
    trust other local users, we recommend you use one of
    <command>initdb</command>'s <option>-W</option>, <option>--pwprompt</option>
    or <option>--pwfile</option> options to assign a password to the
-   database superuser.<indexterm><primary>password</><secondary>of the
-   superuser</></indexterm>  Also, specify <option>-A md5</> or
+   database superuser.<indexterm>
+     <primary>password</>
+     <secondary>of the superuser</>
+   </indexterm>
+   Also, specify <option>-A md5</> or
    <option>-A password</> so that the default <literal>trust</> authentication
    mode is not used; or modify the generated <filename>pg_hba.conf</filename>
    file after running <command>initdb</command>, but
@@ -264,8 +267,11 @@ pg_ctl start -l logfile
 
   <para>
    Normally, you will want to start the database server when the
-   computer boots.<indexterm><primary>booting</><secondary>starting
-   the server during</></> Autostart scripts are operating-system-specific.
+   computer boots.<indexterm>
+     <primary>booting</>
+     <secondary>starting the server during</>
+   </indexterm>
+   Autostart scripts are operating-system-specific.
    There are a few distributed with
    <productname>PostgreSQL</productname> in the
    <filename>contrib/start-scripts</> directory. Installing one will require