sci-mathematics/scilab-5.5.0: Fix minimum version dependency for jlatexmath

Scilab 5.5.0 requires >=dev-java/jlatexmath-1.0.3 and >=dev-java/jlatexmath-fop-1.0.3, which are keyworded. However they are not pulled in since the ebuild does not specify a minimum version for the atom.
Hence if the installed version is < 1.0.3, the configure step fails with :

    checking minimal version (1.0.3) of jlatexmath... configure: error: Wrong version of jlatexmath. Expected at least 1.0.3. Found 1.0.2

This commit adds an explicit minimum version dependency for those packages.