Fix breaking issues introduced in #1894

[covertivy]

Hello,
Following my previous contribution in #1894 I changed the default behavior of the getFile method of the SMBConnection class.
Now it always uses overly permissive share access modes instead of overly restrictive ones.
This is very useful if we wish to read "locked" files (files that have active open process handles to them).
But in doing so I forgot a crucial element of impacket's exec suite.
All of them rely on receiving a STATUS_SHARING_VIOLATION error in order to know when the command stops being executed remotely.
This commit fixes all exec examples and modules.

[anadrianmanrique]

Hi @covertivy, thanks for the PR. We've decided to merge #2044 instead, as we want to have better control on who is actually performing getFile with access to locked files, and also keep the getFile original behavior for those code clients that don't need this particular feature.