ports-mgmt/portgrep: Update to 1.3.0

Changes: https://github.com/dmgk/portgrep/releases/tag/v1.3.0

• Add context options (-A, -B and -C).
• -C was renamed to -M to allow context options to be the same as with grep.
• Add -G option to set custom colors (see ls(1) for color codes). Colors can also be set with PORTGREP_COLORS env variable.
• Custom queries are now interpreted as plain text unless -x was also given.