tweak xml_perser recoverable parse test
tweak xml_perser recoverable parse test

different versions of libxml produce slightly different errors

Konsus/libxml,apeace/libxmljs,improvisio-software/libxmljs,Konsus/libxml,CodeFridge/libxmljs_mem,CodeFridge/libxmljs_mem,rc0x03/libxmljs,rc0x03/libxmljs,rchipka/libxmljs,hildjj/libxmljs,polotek/libxmljs,libxmljs/libxmljs,gagern/libxmljs,rchipka/libxmljs,apeace/libxmljs,sergeche/libxmljs,rc0x03/libxmljs,libxmljs/libxmljs,gagern/libxmljs,Konsus/libxml,gagern/libxmljs,improvisio-software/libxmljs,improvisio-software/libxmljs,polotek/libxmljs,polotek/libxmljs,sergeche/libxmljs,rchipka/libxmljs,Visya/libxmljs,libxmljs/libxmljs,hildjj/libxmljs,hildjj/libxmljs,sergeche/libxmljs,Visya/libxmljs,Visya/libxmljs,CodeFridge/libxmljs_mem