Coverity: geoit can be end() when dereferenced

[chennes]

Coverity has identified a potential bug that this PR seeks to address: in the Sketcher function analyseBlockedGeometry() there is a conditional:

auto geoit = std::find(blockedGeoIds.begin(),blockedGeoIds.end(),c->Second);
if(geoit != blockedGeoIds.end() || onlyblockedGeometry[c->Second]) { // internal alignment geometry found, add to list

and then later on inside that conditional

blockedGeoIds.push_back(*geoit);

However, since the condition is an OR, it is apparently possible that geoit is end(), in which case dereferencing it is illegal. The fix proposed in this PR is to modify the OR to an AND. However, this needs review.

This fix is a joint effort with @hyarion.

[wwmayer]

Replace blockedGeoIds.push_back(*geoit); with blockedGeoIds.push_back(c->Second);

[hyarion]

Just for the record, here's the forum post regarding the proposed fix: https://forum.freecadweb.org/viewtopic.php?p=476886#p476886

[chennes]

Closed in favor of the real fix in #4442