Update configuration file based on PHP 7.3.5.

src/deb/php/php.ini

@@ -1719,6 +1719,11 @@ zend.assertions = -1
 ; Default: mbstring.http_output_conv_mimetype=^(text/|application/xhtml\+xml)
 ;mbstring.http_output_conv_mimetype=
 
+; This directive specifies maximum stack depth for mbstring regular expressions. It is similar
+; to the pcre.recursion_limit for PCRE.
+; Default: 100000
+;mbstring.regex_stack_limit=100000
+
 [gd]
 ; Tell the jpeg decode to ignore warnings and try to create
 ; a gd image. The warning will then be displayed as notices