lib/srdb1: schema - use etag size entity also for pua and xcap tables

(cherry picked from commit 01ba0f334b5a3c2f9cbd5c746c18ac65ecdf44be)

src/lib/srdb1/schema/pr_pua.xml

@@ -80,7 +80,7 @@
     <column id="etag">
         <name>etag</name>
         <type>string</type>
-        <size>&domain_len;</size>
+        <size>&etag_len;</size>
         <description>Etag</description>
     </column>
 

src/lib/srdb1/schema/pr_xcap.xml

@@ -64,7 +64,7 @@
     <column id="etag">
         <name>etag</name>
         <type>string</type>
-        <size>&user_len;</size>
+        <size>&etag_len;</size>
         <description>Document Etag</description>
     </column>