Do not escape ":" in the properties files

[hombit]

Bug report

properties has unnecessary "\" before ":", for example: hats_creation_date=2025-01-24T16\:01UTC. I guess it is because jproperties overthinking the escaping, which is not really required for values, from Java properties docs:

The key contains all of the characters in the line starting with the first non-white space character and up to, but not including, the first unescaped '=', ':', or white space character other than a line terminator.

jproperies package allows turning escaping off with p = Properties(process_escapes_in_values=False), see the relevant discussion here:
Tblue/python-jproperties#3

HiPS specification doesn't suggest escaping ":", the example it gives:

creator_did = ivo://SSC/P/XMM/EPIC
obs_collection = XMM-Newton
obs_title = XMM-Newton stacked EPIC images
obs_ack = HE-Team (Strasbourg), SSC XMM-Newton
obs_copyright = (c) ESA / SSC XMM-Newton
obs_copyright_url = http://xmmssc.irap.omp.eu/
t_min = 51577.46
t_max = 56331.92
obs_regime = X-ray
em_min = 1e-10
em_max = 6e-9
s_pixel_scale = 0.001111
data_pixel_bitpix = 32
dataproduct_type = image
moc_sky_fraction = 0.1404
hips_estsize = 40322637
hips_creation_date = 2015-10-01T14:07Z
client_category = Image/X/XMM
hips_builder = Aladin/HipsGen v8.175
hips_version = 1.4
hips_release_date = 2015-10-05T08:46Z
hips_publisher = SSC XMM-Newton
hips_frame = equatorial
hips_order = 7
hips_tile_width = 512
hips_master_url = http://saada.u-strasbg.fr/xmmallsky
hips_status = public master clonable
hips_tile_format = png fits
hips_pixel_bitpix = 32
hips_hierarchy = mean
hips_pixel_cut = 0 50.95
hips_data_range = -266.5 799.5
hips_pixel_scale = 8.946E-4

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