Fix Runic indentation in parse_variable (#4801)

Co-authored-by: ChrisRackauckas-Claude <accounts@chrisrackauckas.com>

Author: ChrisRackauckas-Claude

lib/ModelingToolkitBase/src/systems/abstractsystem.jl

@@ -3603,7 +3603,7 @@ function parse_variable(sys::AbstractSystem, str::AbstractString)
         for ident in eachsplit(str, ('.', NAMESPACE_SEPARATOR))
             ident = Symbol(ident)
             hasproperty(cur, ident) ||
-            throw(ArgumentError("System $(nameof(cur)) does not have a subsystem/variable named $(ident)"))
+                throw(ArgumentError("System $(nameof(cur)) does not have a subsystem/variable named $(ident)"))
             cur = getproperty(cur, ident)
         end
     else