build-sys: let autogen know we just want to build one lib
build-sys: let autogen know we just want to build one lib

Fix multiply defined messages from automake for indeed identical named
targets for both the .c and .h files.  Just give a name so autogen knows
it should build one lib out of the files given.

zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb