logrotate: version up to 3.15 .

Fixes FTBFS on recent gcc:
logrotate.c: In function 'prerotateSingleLog':
logrotate.c:1328:6: error: 'strncat' specified bound depends on the length of the source argument [-Werror=stringop-overflow=]
      strncat(tempstr, rotNames->baseName, baseLen - extLen);
      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
logrotate.c:1320:19: note: length computed here
  size_t baseLen = strlen(rotNames->baseName);
                   ^~~~~~~~~~~~~~~~~~~~~~~~~~
logrotate.c:1347:2: error: 'strncat' specified bound depends on the length of the source argument [-Werror=stringop-overflow=]
  strncat(tempstr, rotNames->baseName,
  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   strlen(rotNames->baseName) - strlen(log->extension));
   ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
logrotate.c:1348:3: note: length computed here
   strlen(rotNames->baseName) - strlen(log->extension));
   ^~~~~~~~~~~~~~~~~~~~~~~~~~
cc1: all warnings being treated as errors

component/logrotate/buildout.cfg

@@ -8,8 +8,8 @@ parts = logrotate
 [logrotate]
 recipe = slapos.recipe.cmmi
 shared = true
-url = https://github.com/logrotate/logrotate/releases/download/3.11.0/logrotate-3.11.0.tar.xz
-md5sum = 3a9280e4caeb837427a2d54518fbcdac
+url = https://github.com/logrotate/logrotate/releases/download/3.15.0/logrotate-3.15.0.tar.xz
+md5sum = 320046f0b9fc38337e8827d4c5a866a0
 # BBB this is only for backward-compatibility.
 post-install =
   ln -nsf . @@LOCATION@@/usr