Crash on short query

[i582]

For example:

> f VK
readline.js:1280
            throw err;
            ^

<ref *1> Error: spawnSync /bin/sh ENOBUFS
    at Object.spawnSync (internal/child_process.js:1077:20)
    at spawnSync (child_process.js:776:24)
    at Object.execSync (child_process.js:858:15)
    
  errno: -105,
  code: 'ENOBUFS',
  syscall: 'spawnSync /bin/sh',
  path: '/bin/sh',
  spawnargs: [ '-c', 'find ./kphp -iname "*vk*"' ],
  error: [Circular *1],
  status: null,
  signal: 'SIGTERM',
  output: [
    null,
    Buffer(1052672) [Uint8Array] [
       47, 104, 111, 109, 101,  47, 112, 109,  97, 107, 104, 110,
      101, 118,  47, 107, 112, 104, 112,  45,  99, 111, 109, 112,
      105, 108, 101,  47, 107, 112, 104, 112,  47, 111,  95,  54,
       54,  47,  86,  75,  64,  65,  80,  73,  64,  66, 117, 105,
      108, 100, 101, 114, 115,  64,  82, 101, 115, 112, 111, 110,
      115, 101, 115,  64,  87,  97, 108, 108,  64,  71, 101, 116,
       67, 111, 109, 109, 101, 110, 116, 115,  82, 101, 115, 112,
      111, 110, 115, 101,  64,  64, 115, 101, 116,  82, 101,  97,
       99, 116, 105, 111,
      ... 1052572 more items
    ],
    Buffer(0) [Uint8Array] []
  ],
  pid: 14572,
  stdout: Buffer(1052672) [Uint8Array] [
     47, 104, 111, 109, 101,  47, 112, 109,  97, 107, 104, 110,
    101, 118,  47, 107, 112, 104, 112,  45,  99, 111, 109, 112,
    105, 108, 101,  47, 107, 112, 104, 112,  47, 111,  95,  54,
     54,  47,  86,  75,  64,  65,  80,  73,  64,  66, 117, 105,
    108, 100, 101, 114, 115,  64,  82, 101, 115, 112, 111, 110,
    115, 101, 115,  64,  87,  97, 108, 108,  64,  71, 101, 116,
     67, 111, 109, 109, 101, 110, 116, 115,  82, 101, 115, 112,
    111, 110, 115, 101,  64,  64, 115, 101, 116,  82, 101,  97,
     99, 116, 105, 111,
    ... 1052572 more items
  ],
  stderr: Buffer(0) [Uint8Array] []
}

Apparently, the matter is in the number of files, which is very large due to the
fact that the query is so short.
It is necessary to limit the number of files to 50 in order to prevent such crashes
and to be able to show the user a sane description of the problem.