[core] restrict where config "else" clauses occur (#1268)
[core] restrict where config "else" clauses occur (#1268)

(improve validation)

x-ref:
  "condition should be optional in "else" clause in configuration file"
  https://redmine.lighttpd.net/issues/1268

PatchyFog/lighttpd1.4-mbedtls,PatchyFog/lighttpd1.4-mbedtls,lighttpd/lighttpd1.4,lighttpd/lighttpd1.4,gstrauss/lighttpd1.4,PatchyFog/lighttpd1.4-mbedtls,PatchyFog/lighttpd1.4-mbedtls,PatchyFog/lighttpd1.4-mbedtls,PatchyFog/lighttpd1.4-mbedtls,lighttpd/lighttpd1.4,lighttpd/lighttpd1.4,gstrauss/lighttpd1.4,lighttpd/lighttpd1.4,gstrauss/lighttpd1.4,gstrauss/lighttpd1.4,gstrauss/lighttpd1.4,gstrauss/lighttpd1.4,lighttpd/lighttpd1.4,PatchyFog/lighttpd1.4-mbedtls