Remove workaround for icpc std::regex issue (#1136)
Remove workaround for icpc std::regex issue (#1136)

Now works as expected, but workaround fails.

Clsoes #1133
AMICI-developer/AMICI,AMICI-developer/AMICI,FFroehlich/AMICI,FFroehlich/AMICI,AMICI-developer/AMICI,FFroehlich/AMICI,AMICI-developer/AMICI,FFroehlich/AMICI