fix some gcc warnings (#73) * tweak string size fix gcc8 warnings ``` svr-agentfwd.c: In function 'bindagent': svr-agentfwd.c:254:53: warning: '%s' directive output may be truncated writing up to 107 bytes into a region of size between 0 and 107 [-Wformat-truncation=] snprintf(addr.sun_path, sizeof(addr.sun_path), "%s/%s", path, sockfile); ^~ ~~~~~~~~ svr-agentfwd.c:254:2: note: 'snprintf' output between 2 and 216 bytes into a destination of size 108 snprintf(addr.sun_path, sizeof(addr.sun_path), "%s/%s", path, sockfile); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ``` * cleanup signed/unsigned comparison fix gcc8 warnings ``` scp.c: In function 'do_local_cmd': scp.c:132:17: warning: comparison of integer expressions of different signedness: 'u_int' {aka 'unsigned int'} and 'int' [-Wsign-compare] for (i = 0; i < a->num; i++) ^ scpmisc.c: In function 'addargs': scpmisc.c:161:25: warning: comparison of integer expressions of different signedness: 'int' and 'u_int' {aka 'unsigned int'} [-Wsign-compare] } else if (args->num+2 >= nalloc) ^~ scpmisc.c: In function 'replacearg': scpmisc.c:183:12: warning: comparison of integer expressions of different signedness: 'u_int' {aka 'unsigned int'} and 'int' [-Wsign-compare] if (which >= args->num) ^~ scpmisc.c: In function 'freeargs': scpmisc.c:196:17: warning: comparison of integer expressions of different signedness: 'u_int' {aka 'unsigned int'} and 'int' [-Wsign-compare] for (i = 0; i < args->num; i++) ^ ``` see https://cvsweb.openbsd.org/cgi-bin/cvsweb/src/usr.bin/ssh/misc.h.diff?r1=1.16&r2=1.17

-----BEGIN RSA PRIVATE KEY-----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-----END RSA PRIVATE KEY-----