GCC warnings for multichar int constants

[nic11]

To reproduce, build with GCC on Arch (after #2276 is merged):

g++ --version
g++ (GCC) 14.2.1 20240910
Copyright (C) 2024 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

/home/roma/my/skymp/skymp-arch/skymp5-server/cpp/addon/ScampServer.cpp:1141:19: warning: multi-character character constant [-Wmultichar]
 1141 |   if (callType == 'meth') {
      |                   ^~~~~~
/home/roma/my/skymp/skymp-arch/skymp5-server/cpp/addon/ScampServer.cpp:1150:26: warning: multi-character character constant [-Wmultichar]
 1150 |   } else if (callType == 'glob') {
      |                          ^~~~~~
/home/roma/my/skymp/skymp-arch/skymp5-server/cpp/addon/ScampServer.cpp:1191:21: warning: multi-character character constant [-Wmultichar]
 1191 |       callTypeInt = 'meth';
      |                     ^~~~~~
/home/roma/my/skymp/skymp-arch/skymp5-server/cpp/addon/ScampServer.cpp:1193:21: warning: multi-character character constant [-Wmultichar]
 1193 |       callTypeInt = 'glob';
      |                     ^~~~~~
/home/roma/my/skymp/skymp-arch/skymp5-server/cpp/addon/ScampServer.cpp:1465:47: warning: multi-character character constant [-Wmultichar]
 1465 |         int callType = jsThis.IsUndefined() ? 'glob' : 'meth';
      |                                               ^~~~~~
/home/roma/my/skymp/skymp-arch/skymp5-server/cpp/addon/ScampServer.cpp:1465:56: warning: multi-character character constant [-Wmultichar]
 1465 |         int callType = jsThis.IsUndefined() ? 'glob' : 'meth';
      |                                                        ^~~~~~

39c8261#diff-c35c3fcadfee3ad4d1ada7e1172ffc7eac60c0e3c60c369ab71a886a025d37ceR1104