formatcaps.html.in: Kill useless spaces in <pre/>

The <pre/> section is rendered as-is on the page. That is, if all
the lines are prefixed with 4 spaces the rendered page will also
have them. Problem is if we put a box around such <pre/> because
the content might not fix into it.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

docs/formatcaps.html.in

@@ -13,7 +13,7 @@
     interface has been added in 0.2.1 allowing to list the set of supported
     virtualization capabilities on the host:</p>
 
-    <pre>    char * virConnectGetCapabilities (virConnectPtr conn);</pre>
+    <pre>char * virConnectGetCapabilities (virConnectPtr conn);</pre>
 
     <p>The value returned is an XML document listing the virtualization
     capabilities of the host and virtualization engine to which