12813: Uninitialized pointer read
string_values2keys (plugins/syntaxes/string.c)
Commit 2bac5ab553395550af33bf92082877ef6b4c5427 missed to set
an value bvp for the newly added case ((syntax & SYNTAX_DN) &&
(value_flags & SLAPI_ATTR_FLAG_NORMALIZED_CES)), which caused
the uninitialized pointer read. This patch sets bvp for all
3 cases.
(cherry picked from commit 40013a5277599aeba62cb0996bbf9860e2acbe34)