"Internal Error" when delete .git in a open repository

[nledez]

To reproduce:

• Create a repository 'mkdir gitxtest ; cd gitxtest ; git init && git commit --allow-empty -m "Empty commit"'
• Open Gitx "gitx"
• Destroy repository "rm -rf .git"

Kaboom !

`Exception Name: NSInternalInconsistencyException
Description: Lines must have an even number of lines: (
"fatal: Not a git repository (or any of the parent directories): .git\n"
)
User Info: (null)

0 CoreFoundation 0x00007fff82bba0a6 exceptionPreprocess + 198
1 libobjc.A.dylib 0x00007fff8843e3f0 objc_exception_throw + 43
2 CoreFoundation 0x00007fff82bb9ee8 +[NSException raise:format:arguments:] + 104
3 Foundation 0x00007fff8452e6a2 -[NSAssertionHandler handleFailureInMethod:object:file:lineNumber:description:] + 189
4 GitX 0x0000000100022955 -[PBGitIndex(IndexRefreshMethods) dictionaryForLines:] + 232
5 GitX 0x0000000100021e65 -[PBGitIndex(IndexRefreshMethods) readStagedFiles:] + 58
6 CoreFoundation 0x00007fff82b6c47a _CFXNotificationPost + 2554
7 Foundation 0x00007fff8456a846 -[NSNotificationCenter postNotificationName:object:userInfo:] + 64
8 Foundation 0x00007fff84628a7c _performFileHandleSource + 1280
9 CoreFoundation 0x00007fff82b39101 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION + 17
10 CoreFoundation 0x00007fff82b38aed __CFRunLoopDoSources0 + 445
11 CoreFoundation 0x00007fff82b5bdc5 __CFRunLoopRun + 789
12 CoreFoundation 0x00007fff82b5b6b2 CFRunLoopRunSpecific + 290
13 HIToolbox 0x00007fff8da760a4 RunCurrentEventLoopInMode + 209
14 HIToolbox 0x00007fff8da75e42 ReceiveNextEventCommon + 356
15 HIToolbox 0x00007fff8da75cd3 BlockUntilNextEventMatchingListInMode + 62
16 AppKit 0x00007fff8a000613 _DPSNextEvent + 685
17 AppKit 0x00007fff89fffed2 -[NSApplication nextEventMatchingMask:untilDate:inMode:dequeue:] + 128
18 AppKit 0x00007fff89ff7283 -[NSApplication run] + 517
19 AppKit 0x00007fff89f9bcb6 NSApplicationMain + 869
20 GitX 0x0000000100030e43 main + 74
21 GitX 0x0000000100001e14 start + 52`