Linux: Fix code dump when built with -D_GLIBCXX_ASSERTIONS caused by …

…an assert in libstdc++.

The variable has enough capacity so pointer &buffer[0] is valid but since clear method was called, we are not supposed to access element at index 0.
Related to Github issue #896

src/Platform/Unix/Process.cpp

@@ -119,7 +119,6 @@ namespace VeraCrypt
 		throw_sys_if (fcntl (exceptionPipe.GetReadFD(), F_SETFL, O_NONBLOCK) == -1);
 
 		vector <char> buffer (4096), stdOutput (4096), errOutput (4096), exOutput (4096);
-		buffer.clear ();
 		stdOutput.clear ();
 		errOutput.clear ();
 		exOutput.clear ();