pgpool: Fix: primary_routing_query_pattern_list retains old values afte

Fix: primary_routing_query_pattern_list retains old values after reload

This commit fixes an issue where primary_routing_query_pattern_list retained
old regex patterns after configuration reload.

Previously, the old regex array was not cleared during reload, and new values
were simply appended. As a result, patterns from the previous configuration
were not discarded and remained in memory.

This commit ensures that the existing regex pattern array is properly cleared
during reload, so that stale values are removed before new values are applied.

The same issue also affected write_function_list, read_only_function_list,
cache_safe_memqcache_table_list, and cache_unsafe_memqcache_table_list,
and the fix has been applied consistently to these configuration parameters as well.

Discussion: https://github.com/pgpool/pgpool2/issues/151
Backpatch-through: v4.3

Branch
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V4_7_STABLE

Details
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https://git.postgresql.org/gitweb?p=pgpool2.git;a=commitdiff;h=a70e6e82ed476d47e3237722ce78d742b71acfb9

Modified Files
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src/config/pool_config_variables.c | 68 ++++++++++++++++++++++++++++++++++++--
1 file changed, 66 insertions(+), 2 deletions(-)