Header: allocate memory for terminating entry
The names array is terminated by a NULL entry, thus allocate space for
one more than entries.
Fixes: #844
==6708==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x6060000045b8 at pc 0x000000589ee1 bp 0x7ffcd1dee220 sp 0x7ffcd1dee218
READ of size 8 at 0x6060000045b8 thread T0
#0 0x589ee0 in String_freeArray ./XUtils.c:157:23
#1 0x56c9af in Settings_delete ./Settings.c:31:7
#2 0x4ee44b in CommandLine_run ./CommandLine.c:395:4
#3 0x4d6fb2 in main ./htop.c:15:11
#4 0x7ff3b8154e49 in __libc_start_main csu/../csu/libc-start.c:314:16
#5 0x428aa9 in _start (./htop+0x428aa9)
0x6060000045b8 is located 0 bytes to the right of 56-byte region [0x606000004580,0x6060000045b8)
allocated by thread T0 here:
#0 0x4a53f2 in __interceptor_calloc (./htop+0x4a53f2)
#1 0x5890ba in xCalloc ./XUtils.c:55:17
#2 0x50a044 in Header_writeBackToSettings ./Header.c:148:34
#3 0x4de861 in Action_runSetup ./Action.c:91:7
#4 0x4de861 in actionSetup ./Action.c:386:4
#5 0x515caf in MainPanel_eventHandler ./MainPanel.c:106:19
#6 0x56a5c1 in ScreenManager_run ./ScreenManager.c:235:19
#7 0x4ee13b in CommandLine_run ./CommandLine.c:364:4
#8 0x4d6fb2 in main ./htop.c:15:11
#9 0x7ff3b8154e49 in __libc_start_main csu/../csu/libc-start.c:314:16
1 file changed
