Make sure the search results don't overflow the incoming 8192 bytes sized

Make sure the search results don't overflow the incoming 8192 bytes sized
buffer when using the zynaddsubfx-ext-gui .

Because the search results also include the full path of the banks
the maximum message size may vary. Sometimes banks are installed in
/usr/local and sometimes in /usr . For now simply print a warning message
when this happens and continue, for example when searching for "str"
in the bank search under FreeBSD:

guimain.cpp:571 Received too many bytes 9052 > 8192 (ignored)

Signed-off-by: Hans Petter Selasky <hps@selasky.org>