Update documentation URLs to use latest MySQL version of the page

Signed-off-by: William Desportes <williamdes@wdes.fr>

libraries/advisory_rules_generic.txt

@@ -146,7 +146,7 @@ rule 'Query caching method' [!fired('Query cache disabled')]
 	Questions / Uptime
 	value > 100
 	Suboptimal caching method.
-	You are using the MySQL Query cache with a fairly high traffic database. It might be worth considering to use <a href="https://dev.mysql.com/doc/refman/5.5/en/ha-memcached.html">memcached</a> instead of the MySQL Query cache, especially if you have multiple slaves.
+	You are using the MySQL Query cache with a fairly high traffic database. It might be worth considering to use <a href="https://dev.mysql.com/doc/refman/5.6/en/ha-memcached.html">memcached</a> instead of the MySQL Query cache, especially if you have multiple slaves.
 	The query cache is enabled and the server receives %d queries per second. This rule fires if there is more than 100 queries per second. | round(value,1)
 
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@@ -220,7 +220,7 @@ rule 'Temp disk rate' [!fired('Percentage of temp tables on disk')]
 	Created_tmp_disk_tables / Uptime
 	value * 60 * 60 > 1
 	Many temporary tables are being written to disk instead of being kept in memory.
-	Increasing {max_heap_table_size} and {tmp_table_size} might help. However some temporary tables are always being written to disk, independent of the value of these variables. To eliminate these you will have to rewrite your queries to avoid those conditions (Within a temporary table: Presence of a BLOB or TEXT column or presence of a column bigger than 512 bytes) as mentioned in the <a href="https://dev.mysql.com/doc/refman/5.5/en/internal-temporary-tables.html">MySQL Documentation</a>
+	Increasing {max_heap_table_size} and {tmp_table_size} might help. However some temporary tables are always being written to disk, independent of the value of these variables. To eliminate these you will have to rewrite your queries to avoid those conditions (Within a temporary table: Presence of a BLOB or TEXT column or presence of a column bigger than 512 bytes) as mentioned in the <a href="https://dev.mysql.com/doc/refman/8.0/en/internal-temporary-tables.html">MySQL Documentation</a>
 	Rate of temporary tables being written to disk: %s, this value should be less than 1 per hour | ADVISOR_bytime(value,2)
 
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